formcore@1.2.1
Vulnerabilities |
29 via 145 paths |
---|---|
Dependencies |
453 |
Source |
npm |
Find, fix and prevent vulnerabilities in your code.
high severity
- Vulnerable module: handlebars
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › handlebars@3.0.8
Overview
handlebars is an extension to the Mustache templating language.
Affected versions of this package are vulnerable to Prototype Pollution. Templates may alter an Objects' prototype, thus allowing an attacker to execute arbitrary code on the server.
Details
Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as _proto_
, constructor
and prototype
. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype
are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.
There are two main ways in which the pollution of prototypes occurs:
- Unsafe
Object
recursive merge - Property definition by path
Unsafe Object recursive merge
The logic of a vulnerable recursive merge function follows the following high-level model:
merge (target, source)
foreach property of source
if property exists and is an object on both the target and the source
merge(target[property], source[property])
else
target[property] = source[property]
When the source object contains a property named _proto_
defined with Object.defineProperty()
, the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object
and the source of Object
as defined by the attacker. Properties are then copied on the Object
prototype.
Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source)
.
lodash
and Hoek
are examples of libraries susceptible to recursive merge attacks.
Property definition by path
There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)
If the attacker can control the value of “path”, they can set this value to _proto_.myValue
. myValue
is then assigned to the prototype of the class of the object.
Types of attacks
There are a few methods by which Prototype Pollution can be manipulated:
Type | Origin | Short description |
---|---|---|
Denial of service (DoS) | Client | This is the most likely attack. DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf ). The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object . In this case, the code fails and is likely to cause a denial of service. For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail. |
Remote Code Execution | Client | Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation. For example: eval(someobject.someattr) . In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code. |
Property Injection | Client | The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens. For example: if a codebase checks privileges for someuser.isAdmin , then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true , they can then achieve admin privileges. |
Affected environments
The following environments are susceptible to a Prototype Pollution attack:
- Application server
- Web server
How to prevent
- Freeze the prototype— use
Object.freeze (Object.prototype)
. - Require schema validation of JSON input.
- Avoid using unsafe recursive merge functions.
- Consider using objects without prototypes (for example,
Object.create(null)
), breaking the prototype chain and preventing pollution. - As a best practice use
Map
instead ofObject
.
For more information on this vulnerability type:
Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018
Remediation
Upgrade handlebars
to version 4.0.14, 4.1.2 or higher.
References
high severity
- Vulnerable module: handlebars
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › handlebars@3.0.8
Overview
handlebars is a extension to the Mustache templating language.
Affected versions of this package are vulnerable to Prototype Pollution.
Templates may alter an Object's __proto__
and __defineGetter__
properties, which may allow an attacker to execute arbitrary code on the server through crafted payloads.
Details
Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as _proto_
, constructor
and prototype
. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype
are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.
There are two main ways in which the pollution of prototypes occurs:
- Unsafe
Object
recursive merge - Property definition by path
Unsafe Object recursive merge
The logic of a vulnerable recursive merge function follows the following high-level model:
merge (target, source)
foreach property of source
if property exists and is an object on both the target and the source
merge(target[property], source[property])
else
target[property] = source[property]
When the source object contains a property named _proto_
defined with Object.defineProperty()
, the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object
and the source of Object
as defined by the attacker. Properties are then copied on the Object
prototype.
Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source)
.
lodash
and Hoek
are examples of libraries susceptible to recursive merge attacks.
Property definition by path
There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)
If the attacker can control the value of “path”, they can set this value to _proto_.myValue
. myValue
is then assigned to the prototype of the class of the object.
Types of attacks
There are a few methods by which Prototype Pollution can be manipulated:
Type | Origin | Short description |
---|---|---|
Denial of service (DoS) | Client | This is the most likely attack. DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf ). The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object . In this case, the code fails and is likely to cause a denial of service. For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail. |
Remote Code Execution | Client | Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation. For example: eval(someobject.someattr) . In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code. |
Property Injection | Client | The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens. For example: if a codebase checks privileges for someuser.isAdmin , then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true , they can then achieve admin privileges. |
Affected environments
The following environments are susceptible to a Prototype Pollution attack:
- Application server
- Web server
How to prevent
- Freeze the prototype— use
Object.freeze (Object.prototype)
. - Require schema validation of JSON input.
- Avoid using unsafe recursive merge functions.
- Consider using objects without prototypes (for example,
Object.create(null)
), breaking the prototype chain and preventing pollution. - As a best practice use
Map
instead ofObject
.
For more information on this vulnerability type:
Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018
Remediation
Upgrade handlebars
to version 4.3.0, 3.8.0 or higher.
References
high severity
- Vulnerable module: js-yaml
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-svgo@4.2.1 › svgo@0.6.6 › js-yaml@3.6.1
Overview
js-yaml is a human-friendly data serialization language.
Affected versions of this package are vulnerable to Arbitrary Code Execution. When an object with an executable toString()
property used as a map key, it will execute that function. This happens only for load()
, which should not be used with untrusted data anyway. safeLoad()
is not affected because it can't parse functions.
Remediation
Upgrade js-yaml
to version 3.13.1 or higher.
References
high severity
- Vulnerable module: lodash
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › lodash@3.10.1
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › lodash@1.0.2
Overview
lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
Affected versions of this package are vulnerable to Command Injection via template
.
PoC
var _ = require('lodash');
_.template('', { variable: '){console.log(process.env)}; with(obj' })()
Remediation
Upgrade lodash
to version 4.17.21 or higher.
References
high severity
- Vulnerable module: lodash
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › lodash@3.10.1
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › lodash@1.0.2
Overview
lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
Affected versions of this package are vulnerable to Prototype Pollution. The function defaultsDeep
could be tricked into adding or modifying properties of Object.prototype
using a constructor
payload.
PoC by Snyk
const mergeFn = require('lodash').defaultsDeep;
const payload = '{"constructor": {"prototype": {"a0": true}}}'
function check() {
mergeFn({}, JSON.parse(payload));
if (({})[`a0`] === true) {
console.log(`Vulnerable to Prototype Pollution via ${payload}`);
}
}
check();
For more information, check out our blog post
Details
Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as _proto_
, constructor
and prototype
. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype
are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.
There are two main ways in which the pollution of prototypes occurs:
- Unsafe
Object
recursive merge - Property definition by path
Unsafe Object recursive merge
The logic of a vulnerable recursive merge function follows the following high-level model:
merge (target, source)
foreach property of source
if property exists and is an object on both the target and the source
merge(target[property], source[property])
else
target[property] = source[property]
When the source object contains a property named _proto_
defined with Object.defineProperty()
, the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object
and the source of Object
as defined by the attacker. Properties are then copied on the Object
prototype.
Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source)
.
lodash
and Hoek
are examples of libraries susceptible to recursive merge attacks.
Property definition by path
There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)
If the attacker can control the value of “path”, they can set this value to _proto_.myValue
. myValue
is then assigned to the prototype of the class of the object.
Types of attacks
There are a few methods by which Prototype Pollution can be manipulated:
Type | Origin | Short description |
---|---|---|
Denial of service (DoS) | Client | This is the most likely attack. DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf ). The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object . In this case, the code fails and is likely to cause a denial of service. For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail. |
Remote Code Execution | Client | Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation. For example: eval(someobject.someattr) . In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code. |
Property Injection | Client | The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens. For example: if a codebase checks privileges for someuser.isAdmin , then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true , they can then achieve admin privileges. |
Affected environments
The following environments are susceptible to a Prototype Pollution attack:
- Application server
- Web server
How to prevent
- Freeze the prototype— use
Object.freeze (Object.prototype)
. - Require schema validation of JSON input.
- Avoid using unsafe recursive merge functions.
- Consider using objects without prototypes (for example,
Object.create(null)
), breaking the prototype chain and preventing pollution. - As a best practice use
Map
instead ofObject
.
For more information on this vulnerability type:
Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018
Remediation
Upgrade lodash
to version 4.17.12 or higher.
References
high severity
- Vulnerable module: lodash
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › lodash@3.10.1
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › lodash@1.0.2
Overview
lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
Affected versions of this package are vulnerable to Prototype Pollution in zipObjectDeep
due to an incomplete fix for CVE-2020-8203.
Details
Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as _proto_
, constructor
and prototype
. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype
are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.
There are two main ways in which the pollution of prototypes occurs:
- Unsafe
Object
recursive merge - Property definition by path
Unsafe Object recursive merge
The logic of a vulnerable recursive merge function follows the following high-level model:
merge (target, source)
foreach property of source
if property exists and is an object on both the target and the source
merge(target[property], source[property])
else
target[property] = source[property]
When the source object contains a property named _proto_
defined with Object.defineProperty()
, the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object
and the source of Object
as defined by the attacker. Properties are then copied on the Object
prototype.
Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source)
.
lodash
and Hoek
are examples of libraries susceptible to recursive merge attacks.
Property definition by path
There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)
If the attacker can control the value of “path”, they can set this value to _proto_.myValue
. myValue
is then assigned to the prototype of the class of the object.
Types of attacks
There are a few methods by which Prototype Pollution can be manipulated:
Type | Origin | Short description |
---|---|---|
Denial of service (DoS) | Client | This is the most likely attack. DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf ). The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object . In this case, the code fails and is likely to cause a denial of service. For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail. |
Remote Code Execution | Client | Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation. For example: eval(someobject.someattr) . In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code. |
Property Injection | Client | The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens. For example: if a codebase checks privileges for someuser.isAdmin , then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true , they can then achieve admin privileges. |
Affected environments
The following environments are susceptible to a Prototype Pollution attack:
- Application server
- Web server
How to prevent
- Freeze the prototype— use
Object.freeze (Object.prototype)
. - Require schema validation of JSON input.
- Avoid using unsafe recursive merge functions.
- Consider using objects without prototypes (for example,
Object.create(null)
), breaking the prototype chain and preventing pollution. - As a best practice use
Map
instead ofObject
.
For more information on this vulnerability type:
Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018
Remediation
Upgrade lodash
to version 4.17.20 or higher.
References
high severity
- Vulnerable module: lodash
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › lodash@3.10.1
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › lodash@1.0.2
Overview
lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
Affected versions of this package are vulnerable to Prototype Pollution via the setWith
and set
functions.
PoC by awarau
- Create a JS file with this contents:
lod = require('lodash') lod.setWith({}, "__proto__[test]", "123") lod.set({}, "__proto__[test2]", "456") console.log(Object.prototype)
- Execute it with
node
- Observe that
test
andtest2
is now in theObject.prototype
.
Details
Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as _proto_
, constructor
and prototype
. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype
are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.
There are two main ways in which the pollution of prototypes occurs:
- Unsafe
Object
recursive merge - Property definition by path
Unsafe Object recursive merge
The logic of a vulnerable recursive merge function follows the following high-level model:
merge (target, source)
foreach property of source
if property exists and is an object on both the target and the source
merge(target[property], source[property])
else
target[property] = source[property]
When the source object contains a property named _proto_
defined with Object.defineProperty()
, the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object
and the source of Object
as defined by the attacker. Properties are then copied on the Object
prototype.
Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source)
.
lodash
and Hoek
are examples of libraries susceptible to recursive merge attacks.
Property definition by path
There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)
If the attacker can control the value of “path”, they can set this value to _proto_.myValue
. myValue
is then assigned to the prototype of the class of the object.
Types of attacks
There are a few methods by which Prototype Pollution can be manipulated:
Type | Origin | Short description |
---|---|---|
Denial of service (DoS) | Client | This is the most likely attack. DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf ). The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object . In this case, the code fails and is likely to cause a denial of service. For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail. |
Remote Code Execution | Client | Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation. For example: eval(someobject.someattr) . In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code. |
Property Injection | Client | The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens. For example: if a codebase checks privileges for someuser.isAdmin , then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true , they can then achieve admin privileges. |
Affected environments
The following environments are susceptible to a Prototype Pollution attack:
- Application server
- Web server
How to prevent
- Freeze the prototype— use
Object.freeze (Object.prototype)
. - Require schema validation of JSON input.
- Avoid using unsafe recursive merge functions.
- Consider using objects without prototypes (for example,
Object.create(null)
), breaking the prototype chain and preventing pollution. - As a best practice use
Map
instead ofObject
.
For more information on this vulnerability type:
Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018
Remediation
Upgrade lodash
to version 4.17.17 or higher.
References
high severity
- Vulnerable module: lodash
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › lodash@3.10.1
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › lodash@1.0.2
Overview
lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
Affected versions of this package are vulnerable to Prototype Pollution. The functions merge
, mergeWith
, and defaultsDeep
could be tricked into adding or modifying properties of Object.prototype
. This is due to an incomplete fix to CVE-2018-3721
.
Details
Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as _proto_
, constructor
and prototype
. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype
are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.
There are two main ways in which the pollution of prototypes occurs:
- Unsafe
Object
recursive merge - Property definition by path
Unsafe Object recursive merge
The logic of a vulnerable recursive merge function follows the following high-level model:
merge (target, source)
foreach property of source
if property exists and is an object on both the target and the source
merge(target[property], source[property])
else
target[property] = source[property]
When the source object contains a property named _proto_
defined with Object.defineProperty()
, the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object
and the source of Object
as defined by the attacker. Properties are then copied on the Object
prototype.
Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source)
.
lodash
and Hoek
are examples of libraries susceptible to recursive merge attacks.
Property definition by path
There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)
If the attacker can control the value of “path”, they can set this value to _proto_.myValue
. myValue
is then assigned to the prototype of the class of the object.
Types of attacks
There are a few methods by which Prototype Pollution can be manipulated:
Type | Origin | Short description |
---|---|---|
Denial of service (DoS) | Client | This is the most likely attack. DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf ). The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object . In this case, the code fails and is likely to cause a denial of service. For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail. |
Remote Code Execution | Client | Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation. For example: eval(someobject.someattr) . In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code. |
Property Injection | Client | The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens. For example: if a codebase checks privileges for someuser.isAdmin , then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true , they can then achieve admin privileges. |
Affected environments
The following environments are susceptible to a Prototype Pollution attack:
- Application server
- Web server
How to prevent
- Freeze the prototype— use
Object.freeze (Object.prototype)
. - Require schema validation of JSON input.
- Avoid using unsafe recursive merge functions.
- Consider using objects without prototypes (for example,
Object.create(null)
), breaking the prototype chain and preventing pollution. - As a best practice use
Map
instead ofObject
.
For more information on this vulnerability type:
Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018
Remediation
Upgrade lodash
to version 4.17.11 or higher.
References
high severity
- Vulnerable module: lodash.template
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › gulp-util@3.0.8 › lodash.template@3.6.2
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › gulp-util@3.0.8 › lodash.template@3.6.2
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › gulp-util@3.0.8 › lodash.template@3.6.2
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › gulp-util@3.0.8 › lodash.template@3.6.2
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › gulp-util@3.0.8 › lodash.template@3.6.2
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › gulp-util@3.0.8 › lodash.template@3.6.2
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › gulp-util@3.0.8 › lodash.template@3.6.2
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › gulp-util@3.0.8 › lodash.template@3.6.2
Overview
lodash.template is a The Lodash method _.template exported as a Node.js module.
Affected versions of this package are vulnerable to Command Injection via template
.
PoC
var _ = require('lodash');
_.template('', { variable: '){console.log(process.env)}; with(obj' })()
Remediation
There is no fixed version for lodash.template
.
References
high severity
- Vulnerable module: minimatch
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-stream@3.1.18 › minimatch@2.0.10
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-stream@3.1.18 › glob@4.5.3 › minimatch@2.0.10
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › minimatch@0.2.14
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › glob@3.1.21 › minimatch@0.2.14
Overview
minimatch is a minimal matching utility.
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via complicated and illegal regexes.
Details
Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.
The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.
Let’s take the following regular expression as an example:
regex = /A(B|C+)+D/
This regular expression accomplishes the following:
A
The string must start with the letter 'A'(B|C+)+
The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the+
matches one or more times). The+
at the end of this section states that we can look for one or more matches of this section.D
Finally, we ensure this section of the string ends with a 'D'
The expression would match inputs such as ABBD
, ABCCCCD
, ABCBCCCD
and ACCCCCD
It most cases, it doesn't take very long for a regex engine to find a match:
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total
The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.
Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.
Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:
- CCC
- CC+C
- C+CC
- C+C+C.
The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.
From there, the number of steps the engine must use to validate a string just continues to grow.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.
Remediation
Upgrade minimatch
to version 3.0.2 or higher.
References
high severity
- Vulnerable module: minimatch
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-stream@3.1.18 › minimatch@2.0.10Remediation: Open PR to patch minimatch@2.0.10.
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-stream@3.1.18 › glob@4.5.3 › minimatch@2.0.10Remediation: Open PR to patch minimatch@2.0.10.
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › minimatch@0.2.14Remediation: Open PR to patch minimatch@0.2.14.
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › glob@3.1.21 › minimatch@0.2.14Remediation: Open PR to patch minimatch@0.2.14.
Overview
minimatch is a minimal matching utility.
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS).
Details
Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.
The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.
Let’s take the following regular expression as an example:
regex = /A(B|C+)+D/
This regular expression accomplishes the following:
A
The string must start with the letter 'A'(B|C+)+
The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the+
matches one or more times). The+
at the end of this section states that we can look for one or more matches of this section.D
Finally, we ensure this section of the string ends with a 'D'
The expression would match inputs such as ABBD
, ABCCCCD
, ABCBCCCD
and ACCCCCD
It most cases, it doesn't take very long for a regex engine to find a match:
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total
The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.
Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.
Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:
- CCC
- CC+C
- C+CC
- C+C+C.
The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.
From there, the number of steps the engine must use to validate a string just continues to grow.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.
Remediation
Upgrade minimatch
to version 3.0.2 or higher.
References
high severity
- Vulnerable module: url-regex
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › url-regex@3.2.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › url-regex@3.2.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › url-regex@3.2.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › url-regex@3.2.0
Overview
url-regex is a package with regular expression for matching URLs
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS). An attacker providing a very long string in String.test
can cause a Denial of Service.
PoC by Nick Baugh
> require('url-regex')({ strict: false }).test('018137.113.215.4074.138.129.172220.179.206.94180.213.144.175250.45.147.1364868726sgdm6nohQ')
Details
Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.
The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.
Let’s take the following regular expression as an example:
regex = /A(B|C+)+D/
This regular expression accomplishes the following:
A
The string must start with the letter 'A'(B|C+)+
The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the+
matches one or more times). The+
at the end of this section states that we can look for one or more matches of this section.D
Finally, we ensure this section of the string ends with a 'D'
The expression would match inputs such as ABBD
, ABCCCCD
, ABCBCCCD
and ACCCCCD
It most cases, it doesn't take very long for a regex engine to find a match:
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total
The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.
Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.
Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:
- CCC
- CC+C
- C+CC
- C+C+C.
The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.
From there, the number of steps the engine must use to validate a string just continues to grow.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.
Remediation
There is no fixed version for url-regex
.
References
medium severity
- Vulnerable module: @sailshq/lodash
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › merge-defaults@0.2.2 › @sailshq/lodash@3.10.4
Overview
@sailshq/lodash is a fork of Lodash 3.10.x with ongoing maintenance from the Sails core team.
Affected versions of this package are vulnerable to Prototype Pollution. The function zipObjectDeep
can be tricked into adding or modifying properties of the Object prototype. These properties will be present on all objects.
PoC
const _ = require('lodash');
_.zipObjectDeep(['__proto__.z'],[123])
console.log(z) // 123
Details
Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as _proto_
, constructor
and prototype
. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype
are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.
There are two main ways in which the pollution of prototypes occurs:
- Unsafe
Object
recursive merge - Property definition by path
Unsafe Object recursive merge
The logic of a vulnerable recursive merge function follows the following high-level model:
merge (target, source)
foreach property of source
if property exists and is an object on both the target and the source
merge(target[property], source[property])
else
target[property] = source[property]
When the source object contains a property named _proto_
defined with Object.defineProperty()
, the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object
and the source of Object
as defined by the attacker. Properties are then copied on the Object
prototype.
Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source)
.
lodash
and Hoek
are examples of libraries susceptible to recursive merge attacks.
Property definition by path
There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)
If the attacker can control the value of “path”, they can set this value to _proto_.myValue
. myValue
is then assigned to the prototype of the class of the object.
Types of attacks
There are a few methods by which Prototype Pollution can be manipulated:
Type | Origin | Short description |
---|---|---|
Denial of service (DoS) | Client | This is the most likely attack. DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf ). The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object . In this case, the code fails and is likely to cause a denial of service. For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail. |
Remote Code Execution | Client | Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation. For example: eval(someobject.someattr) . In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code. |
Property Injection | Client | The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens. For example: if a codebase checks privileges for someuser.isAdmin , then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true , they can then achieve admin privileges. |
Affected environments
The following environments are susceptible to a Prototype Pollution attack:
- Application server
- Web server
How to prevent
- Freeze the prototype— use
Object.freeze (Object.prototype)
. - Require schema validation of JSON input.
- Avoid using unsafe recursive merge functions.
- Consider using objects without prototypes (for example,
Object.create(null)
), breaking the prototype chain and preventing pollution. - As a best practice use
Map
instead ofObject
.
For more information on this vulnerability type:
Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018
Remediation
There is no fixed version for @sailshq/lodash
.
References
medium severity
- Vulnerable module: decompress
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › decompress@3.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › decompress@3.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › decompress@3.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › decompress@3.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0
Overview
decompress is a package that can be used for extracting archives.
Affected versions of this package are vulnerable to Arbitrary File Write via Archive Extraction (Zip Slip). It is possible to bypass the security measures provided by decompress and conduct ZIP path traversal through symlinks.
PoC
const decompress = require('decompress');
decompress('slip.tar.gz', 'dist').then(files => {
console.log('done!');
});
Details
It is exploited using a specially crafted zip archive, that holds path traversal filenames. When exploited, a filename in a malicious archive is concatenated to the target extraction directory, which results in the final path ending up outside of the target folder. For instance, a zip may hold a file with a "../../file.exe" location and thus break out of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicous file will result in traversing out of the target folder, ending up in /root/.ssh/
overwriting the authorized_keys
file:
+2018-04-15 22:04:29 ..... 19 19 good.txt
+2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Remediation
Upgrade decompress
to version 4.2.1 or higher.
References
medium severity
- Vulnerable module: decompress-tar
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › decompress-tar@3.1.0
Overview
decompress-tar is a tar plugin for decompress.
Affected versions of this package are vulnerable to Arbitrary File Write via Archive Extraction (Zip Slip). It is possible to bypass the security measures provided by decompress and conduct ZIP path traversal through symlinks.
PoC
const decompress = require('decompress');
decompress('slip.tar.gz', 'dist').then(files => {
console.log('done!');
});
Details
It is exploited using a specially crafted zip archive, that holds path traversal filenames. When exploited, a filename in a malicious archive is concatenated to the target extraction directory, which results in the final path ending up outside of the target folder. For instance, a zip may hold a file with a "../../file.exe" location and thus break out of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicous file will result in traversing out of the target folder, ending up in /root/.ssh/
overwriting the authorized_keys
file:
+2018-04-15 22:04:29 ..... 19 19 good.txt
+2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Remediation
There is no fixed version for decompress-tar
.
References
medium severity
- Vulnerable module: glob-parent
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › glob-parent@3.1.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › parse-glob@3.0.4 › glob-base@0.3.0 › glob-parent@2.0.0
Overview
glob-parent is a package that helps extracting the non-magic parent path from a glob string.
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS). The enclosure
regex used to check for strings ending in enclosure containing path separator.
PoC by Yeting Li
var globParent = require("glob-parent")
function build_attack(n) {
var ret = "{"
for (var i = 0; i < n; i++) {
ret += "/"
}
return ret;
}
globParent(build_attack(5000));
Details
Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.
The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.
Let’s take the following regular expression as an example:
regex = /A(B|C+)+D/
This regular expression accomplishes the following:
A
The string must start with the letter 'A'(B|C+)+
The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the+
matches one or more times). The+
at the end of this section states that we can look for one or more matches of this section.D
Finally, we ensure this section of the string ends with a 'D'
The expression would match inputs such as ABBD
, ABCCCCD
, ABCBCCCD
and ACCCCCD
It most cases, it doesn't take very long for a regex engine to find a match:
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total
The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.
Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.
Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:
- CCC
- CC+C
- C+CC
- C+C+C.
The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.
From there, the number of steps the engine must use to validate a string just continues to grow.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.
Remediation
Upgrade glob-parent
to version 5.1.2 or higher.
References
medium severity
- Vulnerable module: handlebars
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › handlebars@3.0.8Remediation: Open PR to patch handlebars@3.0.8.
Overview
handlebars provides the power necessary to let you build semantic templates.
When using attributes without quotes in a handlebars template, an attacker can manipulate the input to introduce additional attributes, potentially executing code. This may lead to a Cross-site Scripting (XSS) vulnerability, assuming an attacker can influence the value entered into the template. If the handlebars template is used to render user-generated content, this vulnerability may escalate to a persistent XSS vulnerability.
Details
Cross-Site Scripting (XSS) attacks occur when an attacker tricks a user’s browser to execute malicious JavaScript code in the context of a victim’s domain. Such scripts can steal the user’s session cookies for the domain, scrape or modify its content, and perform or modify actions on the user’s behalf, actions typically blocked by the browser’s Same Origin Policy.
These attacks are possible by escaping the context of the web application and injecting malicious scripts in an otherwise trusted website. These scripts can introduce additional attributes (say, a "new" option in a dropdown list or a new link to a malicious site) and can potentially execute code on the clients side, unbeknown to the victim. This occurs when characters like <
>
"
'
are not escaped properly.
There are a few types of XSS:
- Persistent XSS is an attack in which the malicious code persists into the web app’s database.
- Reflected XSS is an which the website echoes back a portion of the request. The attacker needs to trick the user into clicking a malicious link (for instance through a phishing email or malicious JS on another page), which triggers the XSS attack.
- DOM-based XSS is an that occurs purely in the browser when client-side JavaScript echoes back a portion of the URL onto the page. DOM-Based XSS is notoriously hard to detect, as the server never gets a chance to see the attack taking place.
Example:
Assume handlebars was used to display user comments and avatar, using the following template:
<img src={{avatarUrl}}><pre>{{comment}}</pre>
If an attacker spoofed their avatar URL and provided the following value:
http://evil.org/avatar.png onload=alert(document.cookie)
The resulting HTML would be the following, triggering the script once the image loads:
<img src=http://evil.org/avatar.png onload=alert(document.cookie)><pre>Gotcha!</pre>
References
medium severity
- Vulnerable module: handlebars
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › handlebars@3.0.8
Overview
handlebars is an extension to the Mustache templating language.
Affected versions of this package are vulnerable to Prototype Pollution. Prototype access to the template engine allows for potential code execution.
Details
Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.
The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.
Let’s take the following regular expression as an example:
regex = /A(B|C+)+D/
This regular expression accomplishes the following:
A
The string must start with the letter 'A'(B|C+)+
The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the+
matches one or more times). The+
at the end of this section states that we can look for one or more matches of this section.D
Finally, we ensure this section of the string ends with a 'D'
The expression would match inputs such as ABBD
, ABCCCCD
, ABCBCCCD
and ACCCCCD
It most cases, it doesn't take very long for a regex engine to find a match:
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total
The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.
Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.
Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:
- CCC
- CC+C
- C+CC
- C+C+C.
The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.
From there, the number of steps the engine must use to validate a string just continues to grow.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.
Remediation
Upgrade handlebars
to version 4.6.0 or higher.
References
medium severity
- Vulnerable module: handlebars
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › handlebars@3.0.8
Overview
handlebars is an extension to the Mustache templating language.
Affected versions of this package are vulnerable to Remote Code Execution (RCE) when selecting certain compiling options to compile templates coming from an untrusted source.
POC
<script src="https://cdn.jsdelivr.net/npm/handlebars@latest/dist/handlebars.js"></script>
<script>
// compile the template
var s = `
{{#with (__lookupGetter__ "__proto__")}}
{{#with (./constructor.getOwnPropertyDescriptor . "valueOf")}}
{{#with ../constructor.prototype}}
{{../../constructor.defineProperty . "hasOwnProperty" ..}}
{{/with}}
{{/with}}
{{/with}}
{{#with "constructor"}}
{{#with split}}
{{pop (push "alert('Vulnerable Handlebars JS when compiling in strict mode');")}}
{{#with .}}
{{#with (concat (lookup join (slice 0 1)))}}
{{#each (slice 2 3)}}
{{#with (apply 0 ../..)}}
{{.}}
{{/with}}
{{/each}}
{{/with}}
{{/with}}
{{/with}}
{{/with}}
`;
var s2 = `{{'a/.") || alert("Vulnerable Handlebars JS when compiling in compat mode'}}`; var template = Handlebars.compile(s, {
strict: true
});
var template = Handlebars.compile(s2, {
compat: true
});
// execute the compiled template and print the output to the console console.log(template({}));
</script>
Remediation
Upgrade handlebars
to version 4.7.7 or higher.
References
medium severity
- Vulnerable module: js-yaml
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-svgo@4.2.1 › svgo@0.6.6 › js-yaml@3.6.1
Overview
js-yaml is a human-friendly data serialization language.
Affected versions of this package are vulnerable to Denial of Service (DoS). The parsing of a specially crafted YAML file may exhaust the system resources.
Details
Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.
The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.
Let’s take the following regular expression as an example:
regex = /A(B|C+)+D/
This regular expression accomplishes the following:
A
The string must start with the letter 'A'(B|C+)+
The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the+
matches one or more times). The+
at the end of this section states that we can look for one or more matches of this section.D
Finally, we ensure this section of the string ends with a 'D'
The expression would match inputs such as ABBD
, ABCCCCD
, ABCBCCCD
and ACCCCCD
It most cases, it doesn't take very long for a regex engine to find a match:
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total
The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.
Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.
Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:
- CCC
- CC+C
- C+CC
- C+C+C.
The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.
From there, the number of steps the engine must use to validate a string just continues to grow.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.
Remediation
Upgrade js-yaml
to version 3.13.0 or higher.
References
medium severity
- Vulnerable module: lodash
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › lodash@3.10.1
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › lodash@1.0.2
Overview
lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
Affected versions of this package are vulnerable to Prototype Pollution. The function zipObjectDeep
can be tricked into adding or modifying properties of the Object prototype. These properties will be present on all objects.
PoC
const _ = require('lodash');
_.zipObjectDeep(['__proto__.z'],[123])
console.log(z) // 123
Details
Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as _proto_
, constructor
and prototype
. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype
are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.
There are two main ways in which the pollution of prototypes occurs:
- Unsafe
Object
recursive merge - Property definition by path
Unsafe Object recursive merge
The logic of a vulnerable recursive merge function follows the following high-level model:
merge (target, source)
foreach property of source
if property exists and is an object on both the target and the source
merge(target[property], source[property])
else
target[property] = source[property]
When the source object contains a property named _proto_
defined with Object.defineProperty()
, the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object
and the source of Object
as defined by the attacker. Properties are then copied on the Object
prototype.
Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source)
.
lodash
and Hoek
are examples of libraries susceptible to recursive merge attacks.
Property definition by path
There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)
If the attacker can control the value of “path”, they can set this value to _proto_.myValue
. myValue
is then assigned to the prototype of the class of the object.
Types of attacks
There are a few methods by which Prototype Pollution can be manipulated:
Type | Origin | Short description |
---|---|---|
Denial of service (DoS) | Client | This is the most likely attack. DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf ). The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object . In this case, the code fails and is likely to cause a denial of service. For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail. |
Remote Code Execution | Client | Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation. For example: eval(someobject.someattr) . In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code. |
Property Injection | Client | The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens. For example: if a codebase checks privileges for someuser.isAdmin , then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true , they can then achieve admin privileges. |
Affected environments
The following environments are susceptible to a Prototype Pollution attack:
- Application server
- Web server
How to prevent
- Freeze the prototype— use
Object.freeze (Object.prototype)
. - Require schema validation of JSON input.
- Avoid using unsafe recursive merge functions.
- Consider using objects without prototypes (for example,
Object.create(null)
), breaking the prototype chain and preventing pollution. - As a best practice use
Map
instead ofObject
.
For more information on this vulnerability type:
Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018
Remediation
Upgrade lodash
to version 4.17.16 or higher.
References
medium severity
- Vulnerable module: lodash
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › lodash@3.10.1Remediation: Open PR to patch lodash@3.10.1.
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › lodash@1.0.2
Overview
lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
Affected versions of this package are vulnerable to Prototype Pollution. The utilities function allow modification of the Object
prototype. If an attacker can control part of the structure passed to this function, they could add or modify an existing property.
PoC by Olivier Arteau (HoLyVieR)
var _= require('lodash');
var malicious_payload = '{"__proto__":{"oops":"It works !"}}';
var a = {};
console.log("Before : " + a.oops);
_.merge({}, JSON.parse(malicious_payload));
console.log("After : " + a.oops);
Details
Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as _proto_
, constructor
and prototype
. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype
are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.
There are two main ways in which the pollution of prototypes occurs:
- Unsafe
Object
recursive merge - Property definition by path
Unsafe Object recursive merge
The logic of a vulnerable recursive merge function follows the following high-level model:
merge (target, source)
foreach property of source
if property exists and is an object on both the target and the source
merge(target[property], source[property])
else
target[property] = source[property]
When the source object contains a property named _proto_
defined with Object.defineProperty()
, the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object
and the source of Object
as defined by the attacker. Properties are then copied on the Object
prototype.
Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source)
.
lodash
and Hoek
are examples of libraries susceptible to recursive merge attacks.
Property definition by path
There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)
If the attacker can control the value of “path”, they can set this value to _proto_.myValue
. myValue
is then assigned to the prototype of the class of the object.
Types of attacks
There are a few methods by which Prototype Pollution can be manipulated:
Type | Origin | Short description |
---|---|---|
Denial of service (DoS) | Client | This is the most likely attack. DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf ). The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object . In this case, the code fails and is likely to cause a denial of service. For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail. |
Remote Code Execution | Client | Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation. For example: eval(someobject.someattr) . In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code. |
Property Injection | Client | The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens. For example: if a codebase checks privileges for someuser.isAdmin , then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true , they can then achieve admin privileges. |
Affected environments
The following environments are susceptible to a Prototype Pollution attack:
- Application server
- Web server
How to prevent
- Freeze the prototype— use
Object.freeze (Object.prototype)
. - Require schema validation of JSON input.
- Avoid using unsafe recursive merge functions.
- Consider using objects without prototypes (for example,
Object.create(null)
), breaking the prototype chain and preventing pollution. - As a best practice use
Map
instead ofObject
.
For more information on this vulnerability type:
Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018
Remediation
Upgrade lodash
to version 4.17.5 or higher.
References
medium severity
- Vulnerable module: lodash
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › lodash@3.10.1
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › lodash@1.0.2
Overview
lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via the toNumber
, trim
and trimEnd
functions.
POC
var lo = require('lodash');
function build_blank (n) {
var ret = "1"
for (var i = 0; i < n; i++) {
ret += " "
}
return ret + "1";
}
var s = build_blank(50000)
var time0 = Date.now();
lo.trim(s)
var time_cost0 = Date.now() - time0;
console.log("time_cost0: " + time_cost0)
var time1 = Date.now();
lo.toNumber(s)
var time_cost1 = Date.now() - time1;
console.log("time_cost1: " + time_cost1)
var time2 = Date.now();
lo.trimEnd(s)
var time_cost2 = Date.now() - time2;
console.log("time_cost2: " + time_cost2)
Details
Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.
The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.
Let’s take the following regular expression as an example:
regex = /A(B|C+)+D/
This regular expression accomplishes the following:
A
The string must start with the letter 'A'(B|C+)+
The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the+
matches one or more times). The+
at the end of this section states that we can look for one or more matches of this section.D
Finally, we ensure this section of the string ends with a 'D'
The expression would match inputs such as ABBD
, ABCCCCD
, ABCBCCCD
and ACCCCCD
It most cases, it doesn't take very long for a regex engine to find a match:
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total
The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.
Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.
Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:
- CCC
- CC+C
- C+CC
- C+C+C.
The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.
From there, the number of steps the engine must use to validate a string just continues to grow.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.
Remediation
Upgrade lodash
to version 4.17.21 or higher.
References
medium severity
- Vulnerable module: lodash
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › lodash@3.10.1
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › vinyl-fs@0.3.14 › glob-watcher@0.0.6 › gaze@0.5.2 › globule@0.1.0 › lodash@1.0.2
Overview
lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS). It parses dates using regex strings, which may cause a slowdown of 2 seconds per 50k characters.
Details
Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.
The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.
Let’s take the following regular expression as an example:
regex = /A(B|C+)+D/
This regular expression accomplishes the following:
A
The string must start with the letter 'A'(B|C+)+
The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the+
matches one or more times). The+
at the end of this section states that we can look for one or more matches of this section.D
Finally, we ensure this section of the string ends with a 'D'
The expression would match inputs such as ABBD
, ABCCCCD
, ABCBCCCD
and ACCCCCD
It most cases, it doesn't take very long for a regex engine to find a match:
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total
The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.
Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.
Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:
- CCC
- CC+C
- C+CC
- C+C+C.
The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.
From there, the number of steps the engine must use to validate a string just continues to grow.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.
Remediation
Upgrade lodash
to version 4.17.11 or higher.
References
medium severity
- Vulnerable module: minimist
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › handlebars@3.0.8 › optimist@0.6.1 › minimist@0.0.10
Overview
minimist is a parse argument options module.
Affected versions of this package are vulnerable to Prototype Pollution. The library could be tricked into adding or modifying properties of Object.prototype
using a constructor
or __proto__
payload.
PoC by Snyk
require('minimist')('--__proto__.injected0 value0'.split(' '));
console.log(({}).injected0 === 'value0'); // true
require('minimist')('--constructor.prototype.injected1 value1'.split(' '));
console.log(({}).injected1 === 'value1'); // true
Details
Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as _proto_
, constructor
and prototype
. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype
are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.
There are two main ways in which the pollution of prototypes occurs:
- Unsafe
Object
recursive merge - Property definition by path
Unsafe Object recursive merge
The logic of a vulnerable recursive merge function follows the following high-level model:
merge (target, source)
foreach property of source
if property exists and is an object on both the target and the source
merge(target[property], source[property])
else
target[property] = source[property]
When the source object contains a property named _proto_
defined with Object.defineProperty()
, the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object
and the source of Object
as defined by the attacker. Properties are then copied on the Object
prototype.
Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source)
.
lodash
and Hoek
are examples of libraries susceptible to recursive merge attacks.
Property definition by path
There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)
If the attacker can control the value of “path”, they can set this value to _proto_.myValue
. myValue
is then assigned to the prototype of the class of the object.
Types of attacks
There are a few methods by which Prototype Pollution can be manipulated:
Type | Origin | Short description |
---|---|---|
Denial of service (DoS) | Client | This is the most likely attack. DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf ). The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object . In this case, the code fails and is likely to cause a denial of service. For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail. |
Remote Code Execution | Client | Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation. For example: eval(someobject.someattr) . In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code. |
Property Injection | Client | The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens. For example: if a codebase checks privileges for someuser.isAdmin , then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true , they can then achieve admin privileges. |
Affected environments
The following environments are susceptible to a Prototype Pollution attack:
- Application server
- Web server
How to prevent
- Freeze the prototype— use
Object.freeze (Object.prototype)
. - Require schema validation of JSON input.
- Avoid using unsafe recursive merge functions.
- Consider using objects without prototypes (for example,
Object.create(null)
), breaking the prototype chain and preventing pollution. - As a best practice use
Map
instead ofObject
.
For more information on this vulnerability type:
Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018
Remediation
Upgrade minimist
to version 0.2.1, 1.2.3 or higher.
References
medium severity
- Vulnerable module: semver-regex
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-wrapper@3.0.2 › bin-version-check@2.1.0 › bin-version@1.0.4 › find-versions@1.2.1 › semver-regex@1.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-wrapper@3.0.2 › bin-version-check@2.1.0 › bin-version@1.0.4 › find-versions@1.2.1 › semver-regex@1.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-wrapper@3.0.2 › bin-version-check@2.1.0 › bin-version@1.0.4 › find-versions@1.2.1 › semver-regex@1.0.0
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-wrapper@3.0.2 › bin-version-check@2.1.0 › bin-version@1.0.4 › find-versions@1.2.1 › semver-regex@1.0.0
Overview
semver-regex is a Regular expression for matching semver versions
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS).
PoC
// import of the vulnerable library
const semverRegex = require('semver-regex');
// import of measurement tools
const { PerformanceObserver, performance } = require('perf_hooks');
// config of measurements tools
const obs = new PerformanceObserver((items) => {
console.log(items.getEntries()[0].duration);
performance.clearMarks();
});
obs.observe({ entryTypes: ['measure'] });
// base version string
let version = "v1.1.3-0a"
// Adding the evil code, resulting in string
// v1.1.3-0aa.aa.aa.aa.aa.aa.a…a.a"
for(let i=0; i < 20; i++) {
version += "a.a"
}
// produce a good version
// Parses well for the regex in milliseconds
let goodVersion = version + "2"
// good version proof
performance.mark("good before")
const goodresult = semverRegex().test(goodVersion);
performance.mark("good after")
console.log(`Good result: ${goodresult}`)
performance.measure('Good', 'good before', 'good after');
// create a bad/exploit version that is invalid due to the last $ sign
// will cause the nodejs engine to hang, if not, increase the a.a
// additions above a bit.
badVersion = version + "aaaaaaa$"
// exploit proof
performance.mark("bad before")
const badresult = semverRegex().test(badVersion);
performance.mark("bad after")
console.log(`Bad result: ${badresult}`)
performance.measure('Bad', 'bad before', 'bad after');
Details
Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.
The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.
Let’s take the following regular expression as an example:
regex = /A(B|C+)+D/
This regular expression accomplishes the following:
A
The string must start with the letter 'A'(B|C+)+
The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the+
matches one or more times). The+
at the end of this section states that we can look for one or more matches of this section.D
Finally, we ensure this section of the string ends with a 'D'
The expression would match inputs such as ABBD
, ABCCCCD
, ABCBCCCD
and ACCCCCD
It most cases, it doesn't take very long for a regex engine to find a match:
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total
The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.
Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.
Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:
- CCC
- CC+C
- C+CC
- C+C+C.
The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.
From there, the number of steps the engine must use to validate a string just continues to grow.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.
Remediation
Upgrade semver-regex
to version 3.1.2 or higher.
References
medium severity
- Vulnerable module: tunnel-agent
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › download@4.4.3 › caw@1.2.0 › tunnel-agent@0.4.3Remediation: Open PR to patch tunnel-agent@0.4.3.
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Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › download@4.4.3 › caw@1.2.0 › tunnel-agent@0.4.3Remediation: Open PR to patch tunnel-agent@0.4.3.
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Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › download@4.4.3 › caw@1.2.0 › tunnel-agent@0.4.3Remediation: Open PR to patch tunnel-agent@0.4.3.
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Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › download@4.4.3 › caw@1.2.0 › tunnel-agent@0.4.3Remediation: Open PR to patch tunnel-agent@0.4.3.
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Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-wrapper@3.0.2 › download@4.4.3 › caw@1.2.0 › tunnel-agent@0.4.3Remediation: Open PR to patch tunnel-agent@0.4.3.
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Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-wrapper@3.0.2 › download@4.4.3 › caw@1.2.0 › tunnel-agent@0.4.3Remediation: Open PR to patch tunnel-agent@0.4.3.
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Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-wrapper@3.0.2 › download@4.4.3 › caw@1.2.0 › tunnel-agent@0.4.3Remediation: Open PR to patch tunnel-agent@0.4.3.
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Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-wrapper@3.0.2 › download@4.4.3 › caw@1.2.0 › tunnel-agent@0.4.3Remediation: Open PR to patch tunnel-agent@0.4.3.
Overview
tunnel-agent
is HTTP proxy tunneling agent. Affected versions of the package are vulnerable to Uninitialized Memory Exposure.
A possible memory disclosure vulnerability exists when a value of type number
is used to set the proxy.auth option of a request request
and results in a possible uninitialized memory exposures in the request body.
This is a result of unobstructed use of the Buffer
constructor, whose insecure default constructor increases the odds of memory leakage.
Details
Constructing a Buffer
class with integer N
creates a Buffer
of length N
with raw (not "zero-ed") memory.
In the following example, the first call would allocate 100 bytes of memory, while the second example will allocate the memory needed for the string "100":
// uninitialized Buffer of length 100
x = new Buffer(100);
// initialized Buffer with value of '100'
x = new Buffer('100');
tunnel-agent
's request
construction uses the default Buffer
constructor as-is, making it easy to append uninitialized memory to an existing list. If the value of the buffer list is exposed to users, it may expose raw server side memory, potentially holding secrets, private data and code. This is a similar vulnerability to the infamous Heartbleed
flaw in OpenSSL.
Proof of concept by ChALkeR
require('request')({
method: 'GET',
uri: 'http://www.example.com',
tunnel: true,
proxy:{
protocol: 'http:',
host:"127.0.0.1",
port:8080,
auth:80
}
});
You can read more about the insecure Buffer
behavior on our blog.
Similar vulnerabilities were discovered in request, mongoose, ws and sequelize.
Remediation
Upgrade tunnel-agent
to version 0.6.0 or higher.
Note This is vulnerable only for Node <=4
References
medium severity
- Vulnerable module: xmldom
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › xmldom@0.1.31
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › directory-encoder@0.9.2 › img-stats@0.5.2 › xmldom@0.1.31
Overview
xmldom is an A pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module.
Affected versions of this package are vulnerable to XML External Entity (XXE) Injection. Does not correctly preserve system identifiers, FPIs or namespaces when repeatedly parsing and serializing maliciously crafted documents.
Details
XXE Injection is a type of attack against an application that parses XML input. XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. By default, many XML processors allow specification of an external entity, a URI that is dereferenced and evaluated during XML processing. When an XML document is being parsed, the parser can make a request and include the content at the specified URI inside of the XML document.
Attacks can include disclosing local files, which may contain sensitive data such as passwords or private user data, using file: schemes or relative paths in the system identifier.
For example, below is a sample XML document, containing an XML element- username.
<?xml version="1.0" encoding="ISO-8859-1"?>
<username>John</username>
</xml>
An external XML entity - xxe
, is defined using a system identifier and present within a DOCTYPE header. These entities can access local or remote content. For example the below code contains an external XML entity that would fetch the content of /etc/passwd
and display it to the user rendered by username
.
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
<!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
<username>&xxe;</username>
</xml>
Other XXE Injection attacks can access local resources that may not stop returning data, possibly impacting application availability and leading to Denial of Service.
Remediation
Upgrade xmldom
to version 0.5.0 or higher.
References
low severity
- Vulnerable module: braces
- Introduced through: grunt-grunticon@2.3.2
Detailed paths
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-wrapper@3.0.2 › download@4.4.3 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-build@2.2.0 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-gifsicle@4.2.0 › gifsicle@3.0.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-jpegtran@4.3.2 › jpegtran-bin@3.2.0 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-optipng@4.3.0 › optipng-bin@3.1.4 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
-
Introduced through: formcore@1.2.1 › grunt-grunticon@2.3.2 › grunticon-lib@1.2.3 › svg-to-png@3.1.2 › imagemin@3.1.0 › imagemin-pngquant@4.2.2 › pngquant-bin@3.1.1 › bin-wrapper@3.0.2 › download@4.4.3 › gulp-decompress@1.2.0 › decompress@3.0.0 › vinyl-fs@2.4.4 › glob-stream@5.3.5 › micromatch@2.3.11 › braces@1.8.5
Overview
braces is a Bash-like brace expansion, implemented in JavaScript.
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS). It used a regular expression (^\{(,+(?:(\{,+\})*),*|,*(?:(\{,+\})*),+)\}
) in order to detects empty braces. This can cause an impact of about 10 seconds matching time for data 50K characters long.
Disclosure Timeline
- Feb 15th, 2018 - Initial Disclosure to package owner
- Feb 16th, 2018 - Initial Response from package owner
- Feb 18th, 2018 - Fix issued
- Feb 19th, 2018 - Vulnerability published
Details
Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.
The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.
Let’s take the following regular expression as an example:
regex = /A(B|C+)+D/
This regular expression accomplishes the following:
A
The string must start with the letter 'A'(B|C+)+
The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the+
matches one or more times). The+
at the end of this section states that we can look for one or more matches of this section.D
Finally, we ensure this section of the string ends with a 'D'
The expression would match inputs such as ABBD
, ABCCCCD
, ABCBCCCD
and ACCCCCD
It most cases, it doesn't take very long for a regex engine to find a match:
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total
$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total
The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.
Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.
Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:
- CCC
- CC+C
- C+CC
- C+C+C.
The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.
From there, the number of steps the engine must use to validate a string just continues to grow.
String | Number of C's | Number of steps |
---|---|---|
ACCCX | 3 | 38 |
ACCCCX | 4 | 71 |
ACCCCCX | 5 | 136 |
ACCCCCCCCCCCCCCX | 14 | 65,553 |
By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.
Remediation
Upgrade braces
to version 2.3.1 or higher.