Find, fix and prevent vulnerabilities in your code.
high severity
- Vulnerable module: lodash
- Introduced through: assets-webpack-plugin@3.10.0
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › assets-webpack-plugin@3.10.0 › lodash@4.17.15Remediation: Upgrade to assets-webpack-plugin@4.0.0.
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 mergeProperty 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
Web browser
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: shell-quote
- Introduced through: react-dev-utils@5.0.2 and error-overlay-webpack-plugin@0.1.7
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › react-dev-utils@5.0.2 › shell-quote@1.6.1Remediation: Upgrade to react-dev-utils@12.0.0.
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › shell-quote@1.6.1Remediation: Upgrade to error-overlay-webpack-plugin@1.1.0.
Overview
shell-quote is a package used to quote and parse shell commands.
Affected versions of this package are vulnerable to Remote Code Execution (RCE). An attacker can inject unescaped shell metacharacters through a regex designed to support Windows drive letters. If the output of this package is passed to a real shell as a quoted argument to a command with exec(), an attacker can inject arbitrary commands. This is because the Windows drive letter regex character class is {A-z]
instead of the correct {A-Za-z]
. Several shell metacharacters exist in the space between capital letter Z and lower case letter a, such as the backtick character.
Remediation
Upgrade shell-quote
to version 1.7.3 or higher.
References
high severity
- Vulnerable module: ansi-regex
- Introduced through: react-dev-utils@5.0.2, webpack-dev-server@3.11.3 and others
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › react-dev-utils@5.0.2 › strip-ansi@3.0.1 › ansi-regex@2.1.1Remediation: Upgrade to react-dev-utils@6.0.0.
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › strip-ansi@3.0.1 › ansi-regex@2.1.1Remediation: Upgrade to webpack-dev-server@4.0.0.
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › friendly-errors-webpack-plugin@1.7.0 › chalk@1.1.3 › has-ansi@2.0.0 › ansi-regex@2.1.1
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › react-dev-utils@5.0.2 › chalk@1.1.3 › has-ansi@2.0.0 › ansi-regex@2.1.1
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › friendly-errors-webpack-plugin@1.7.0 › chalk@1.1.3 › strip-ansi@3.0.1 › ansi-regex@2.1.1
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › react-dev-utils@5.0.2 › chalk@1.1.3 › strip-ansi@3.0.1 › ansi-regex@2.1.1
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › react-dev-utils@5.0.2 › babel-code-frame@6.26.0 › chalk@1.1.3 › has-ansi@2.0.0 › ansi-regex@2.1.1
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › react-dev-utils@5.0.2 › babel-code-frame@6.26.0 › chalk@1.1.3 › strip-ansi@3.0.1 › ansi-regex@2.1.1
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › babel-code-frame@6.26.0 › chalk@1.1.3 › has-ansi@2.0.0 › ansi-regex@2.1.1
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › babel-code-frame@6.26.0 › chalk@1.1.3 › strip-ansi@3.0.1 › ansi-regex@2.1.1
Overview
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) due to the sub-patterns [[\\]()#;?]*
and (?:;[-a-zA-Z\\d\\/#&.:=?%@~_]*)*
.
PoC
import ansiRegex from 'ansi-regex';
for(var i = 1; i <= 50000; i++) {
var time = Date.now();
var attack_str = "\u001B["+";".repeat(i*10000);
ansiRegex().test(attack_str)
var time_cost = Date.now() - time;
console.log("attack_str.length: " + attack_str.length + ": " + time_cost+" ms")
}
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 ansi-regex
to version 3.0.1, 4.1.1, 5.0.1, 6.0.1 or higher.
References
high severity
- Vulnerable module: immer
- Introduced through: error-overlay-webpack-plugin@0.1.7
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › immer@1.10.0Remediation: Upgrade to error-overlay-webpack-plugin@0.4.2.
Overview
immer is a package that allows you to create your next immutable state by mutating the current one.
Affected versions of this package are vulnerable to Prototype Pollution.
PoC
const {applyPatches, enablePatches} = require("immer");
enablePatches();
let obj = {};
console.log("Before : " + obj.polluted);
applyPatches({}, [ { op: 'add', path: [ "__proto__", "polluted" ], value: "yes" } ]);
// applyPatches({}, [ { op: 'replace', path: [ "__proto__", "polluted" ], value: "yes" } ]);
console.log("After : " + obj.polluted);
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 mergeProperty 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
Web browser
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 immer
to version 8.0.1 or higher.
References
high severity
- Vulnerable module: loader-utils
- Introduced through: error-overlay-webpack-plugin@0.1.7
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › loader-utils@1.2.3Remediation: Upgrade to error-overlay-webpack-plugin@1.1.0.
Overview
Affected versions of this package are vulnerable to Prototype Pollution in parseQuery
function via the name variable in parseQuery.js
. This pollutes the prototype of the object returned by parseQuery
and not the global Object prototype (which is the commonly understood definition of Prototype Pollution). Therefore, the actual impact will depend on how applications utilize the returned object and how they filter unwanted keys.
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 mergeProperty 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
Web browser
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 loader-utils
to version 1.4.1, 2.0.3 or higher.
References
high severity
new
- Vulnerable module: lodash
- Introduced through: assets-webpack-plugin@3.10.0
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › assets-webpack-plugin@3.10.0 › lodash@4.17.15Remediation: Upgrade to assets-webpack-plugin@4.0.0.
Overview
lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
Affected versions of this package are vulnerable to Prototype Pollution through the zipObjectDeep
function due to improper user input sanitization in the baseZipObject
function.
PoC
lodash.zipobjectdeep:
const zipObjectDeep = require("lodash.zipobjectdeep");
let emptyObject = {};
console.log(`[+] Before prototype pollution : ${emptyObject.polluted}`);
//[+] Before prototype pollution : undefined
zipObjectDeep(["constructor.prototype.polluted"], [true]);
//we inject our malicious attributes in the vulnerable function
console.log(`[+] After prototype pollution : ${emptyObject.polluted}`);
//[+] After prototype pollution : true
lodash:
const test = require("lodash");
let emptyObject = {};
console.log(`[+] Before prototype pollution : ${emptyObject.polluted}`);
//[+] Before prototype pollution : undefined
test.zipObjectDeep(["constructor.prototype.polluted"], [true]);
//we inject our malicious attributes in the vulnerable function
console.log(`[+] After prototype pollution : ${emptyObject.polluted}`);
//[+] After prototype pollution : 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 mergeProperty 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
Web browser
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: unset-value
- Introduced through: webpack@4.47.0, webpack-dev-server@3.11.3 and others
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › micromatch@3.1.10 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › micromatch@3.1.10 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › micromatch@3.1.10 › extglob@2.0.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › micromatch@3.1.10 › nanomatch@1.2.13 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › http-proxy-middleware@0.19.1 › micromatch@3.1.10 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › http-proxy-middleware@0.19.1 › micromatch@3.1.10 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › micromatch@3.1.10 › extglob@2.0.4 › expand-brackets@2.1.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › http-proxy-middleware@0.19.1 › micromatch@3.1.10 › extglob@2.0.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › http-proxy-middleware@0.19.1 › micromatch@3.1.10 › nanomatch@1.2.13 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › micromatch@3.1.10 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › micromatch@3.1.10 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › http-proxy-middleware@0.19.1 › micromatch@3.1.10 › extglob@2.0.4 › expand-brackets@2.1.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › extglob@2.0.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › extglob@2.0.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › micromatch@3.1.10 › extglob@2.0.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › nanomatch@1.2.13 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › nanomatch@1.2.13 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › micromatch@3.1.10 › nanomatch@1.2.13 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › globby@8.0.2 › fast-glob@2.2.7 › micromatch@3.1.10 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › globby@8.0.2 › fast-glob@2.2.7 › micromatch@3.1.10 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › extglob@2.0.4 › expand-brackets@2.1.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › extglob@2.0.4 › expand-brackets@2.1.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › micromatch@3.1.10 › extglob@2.0.4 › expand-brackets@2.1.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › globby@8.0.2 › fast-glob@2.2.7 › micromatch@3.1.10 › extglob@2.0.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › globby@8.0.2 › fast-glob@2.2.7 › micromatch@3.1.10 › nanomatch@1.2.13 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › braces@2.3.2 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › globby@8.0.2 › fast-glob@2.2.7 › micromatch@3.1.10 › extglob@2.0.4 › expand-brackets@2.1.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › extglob@2.0.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › extglob@2.0.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › extglob@2.0.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › extglob@2.0.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › nanomatch@1.2.13 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › nanomatch@1.2.13 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › nanomatch@1.2.13 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › nanomatch@1.2.13 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › extglob@2.0.4 › expand-brackets@2.1.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
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Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › anymatch@2.0.0 › micromatch@3.1.10 › extglob@2.0.4 › expand-brackets@2.1.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › extglob@2.0.4 › expand-brackets@2.1.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › readdirp@2.2.1 › micromatch@3.1.10 › extglob@2.0.4 › expand-brackets@2.1.4 › snapdragon@0.8.2 › base@0.11.2 › cache-base@1.0.1 › unset-value@1.0.0
Overview
Affected versions of this package are vulnerable to Prototype Pollution via the unset
function in index.js
, because it allows access to object prototype properties.
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 mergeProperty 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
Web browser
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 unset-value
to version 2.0.1 or higher.
References
high severity
- Vulnerable module: webpack-dev-middleware
- Introduced through: webpack-dev-server@3.11.3
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › webpack-dev-middleware@3.7.3Remediation: Upgrade to webpack-dev-server@4.0.0.
Overview
Affected versions of this package are vulnerable to Path Traversal due to insufficient validation of the supplied URL address before returning the local file. This issue allows accessing any file on the developer's machine. The middleware can operate with either the physical filesystem or a virtualized in-memory memfs
filesystem. When the writeToDisk
configuration option is set to true
, the physical filesystem is utilized. The getFilenameFromUrl
method parses the URL and constructs the local file path by stripping the public path prefix from the URL and appending the unescaped
path suffix to the outputPath
. Since the URL is not unescaped and normalized automatically before calling the middleware, it is possible to use %2e
and %2f
sequences to perform a path traversal attack.
Notes:
This vulnerability is exploitable without any specific configurations, allowing an attacker to access and exfiltrate content from any file on the developer's machine.
If the development server is exposed on a public IP address or
0.0.0.0
, an attacker on the local network can access the files without victim interaction.If the server permits access from third-party domains, a malicious link could lead to local file exfiltration when visited by the victim.
PoC
A blank project can be created containing the following configuration file webpack.config.js:
module.exports = { devServer: { devMiddleware: { writeToDisk: true } } };
When started, it is possible to access any local file, e.g. /etc/passwd:
$ curl localhost:8080/public/..%2f..%2f..%2f..%2f../etc/passwd
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
Remediation
Upgrade webpack-dev-middleware
to version 5.3.4, 6.1.2, 7.1.0 or higher.
References
high severity
- Vulnerable module: lodash
- Introduced through: assets-webpack-plugin@3.10.0
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › assets-webpack-plugin@3.10.0 › lodash@4.17.15Remediation: Upgrade to assets-webpack-plugin@4.0.0.
Overview
lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
Affected versions of this package are vulnerable to Prototype Pollution via the set
and setwith
functions due to improper user input sanitization.
PoC
lod = require('lodash')
lod.set({}, "__proto__[test2]", "456")
console.log(Object.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 mergeProperty 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
Web browser
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: node-forge
- Introduced through: webpack-dev-server@3.11.3
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › selfsigned@1.10.14 › node-forge@0.10.0Remediation: Upgrade to webpack-dev-server@4.7.3.
Overview
node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.
Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature due to RSA's PKCS#1
v1.5 signature verification code which does not check for tailing garbage bytes after decoding a DigestInfo
ASN.1 structure. This can allow padding bytes to be removed and garbage data added to forge a signature when a low public exponent is being used.
Remediation
Upgrade node-forge
to version 1.3.0 or higher.
References
high severity
- Vulnerable module: lodash
- Introduced through: assets-webpack-plugin@3.10.0
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › assets-webpack-plugin@3.10.0 › lodash@4.17.15Remediation: Upgrade to assets-webpack-plugin@4.0.0.
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
medium severity
- Vulnerable module: eventsource
- Introduced through: react-dev-utils@5.0.2
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › react-dev-utils@5.0.2 › sockjs-client@1.1.5 › eventsource@0.1.6Remediation: Upgrade to react-dev-utils@7.0.2.
Overview
Affected versions of this package are vulnerable to Information Exposure by allowing cookies and the authorization headers to be leaked to external sites.
Remediation
Upgrade eventsource
to version 1.1.1, 2.0.2 or higher.
References
medium severity
- Vulnerable module: node-fetch
- Introduced through: isomorphic-fetch@2.2.1 and glamor@2.20.40
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › isomorphic-fetch@2.2.1 › node-fetch@1.7.3Remediation: Upgrade to isomorphic-fetch@3.0.0.
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › glamor@2.20.40 › fbjs@0.8.18 › isomorphic-fetch@2.2.1 › node-fetch@1.7.3
Overview
node-fetch is a light-weight module that brings window.fetch to node.js
Affected versions of this package are vulnerable to Information Exposure when fetching a remote url with Cookie, if it get a Location
response header, it will follow that url and try to fetch that url with provided cookie. This can lead to forwarding secure headers to 3th party.
Remediation
Upgrade node-fetch
to version 2.6.7, 3.1.1 or higher.
References
medium severity
- Vulnerable module: node-forge
- Introduced through: webpack-dev-server@3.11.3
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › selfsigned@1.10.14 › node-forge@0.10.0Remediation: Upgrade to webpack-dev-server@4.7.3.
Overview
node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.
Affected versions of this package are vulnerable to Prototype Pollution via the forge.debug
API if called with untrusted input.
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 mergeProperty 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
Web browser
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 node-forge
to version 1.0.0 or higher.
References
medium severity
- Vulnerable module: inflight
- Introduced through: clean-webpack-plugin@0.1.19, webpack-dev-server@3.11.3 and others
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › clean-webpack-plugin@0.1.19 › rimraf@2.7.1 › glob@7.2.3 › inflight@1.0.6
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › del@4.1.1 › rimraf@2.7.1 › glob@7.2.3 › inflight@1.0.6
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › globby@8.0.2 › glob@7.2.3 › inflight@1.0.6
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › terser-webpack-plugin@1.4.5 › cacache@12.0.4 › glob@7.2.3 › inflight@1.0.6
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › del@4.1.1 › globby@6.1.0 › glob@7.2.3 › inflight@1.0.6
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › terser-webpack-plugin@1.4.5 › cacache@12.0.4 › rimraf@2.7.1 › glob@7.2.3 › inflight@1.0.6
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › terser-webpack-plugin@1.4.5 › cacache@12.0.4 › move-concurrently@1.0.1 › rimraf@2.7.1 › glob@7.2.3 › inflight@1.0.6
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › terser-webpack-plugin@1.4.5 › cacache@12.0.4 › move-concurrently@1.0.1 › copy-concurrently@1.0.5 › rimraf@2.7.1 › glob@7.2.3 › inflight@1.0.6
Overview
Affected versions of this package are vulnerable to Missing Release of Resource after Effective Lifetime via the makeres
function due to improperly deleting keys from the reqs
object after execution of callbacks. This behavior causes the keys to remain in the reqs
object, which leads to resource exhaustion.
Exploiting this vulnerability results in crashing the node
process or in the application crash.
Note: This library is not maintained, and currently, there is no fix for this issue. To overcome this vulnerability, several dependent packages have eliminated the use of this library.
To trigger the memory leak, an attacker would need to have the ability to execute or influence the asynchronous operations that use the inflight module within the application. This typically requires access to the internal workings of the server or application, which is not commonly exposed to remote users. Therefore, “Attack vector” is marked as “Local”.
PoC
const inflight = require('inflight');
function testInflight() {
let i = 0;
function scheduleNext() {
let key = `key-${i++}`;
const callback = () => {
};
for (let j = 0; j < 1000000; j++) {
inflight(key, callback);
}
setImmediate(scheduleNext);
}
if (i % 100 === 0) {
console.log(process.memoryUsage());
}
scheduleNext();
}
testInflight();
Remediation
There is no fixed version for inflight
.
References
medium severity
- Vulnerable module: serialize-javascript
- Introduced through: webpack@4.47.0
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › terser-webpack-plugin@1.4.5 › serialize-javascript@4.0.0Remediation: Upgrade to webpack@5.1.1.
Overview
serialize-javascript is a package to serialize JavaScript to a superset of JSON that includes regular expressions and functions.
Affected versions of this package are vulnerable to Cross-site Scripting (XSS) due to unsanitized URLs. An Attacker can introduce unsafe HTML
characters through non-http URLs
.
PoC
const serialize = require('serialize-javascript');
let x = serialize({
x: new URL("x:</script>")
});
console.log(x)
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser’s Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, <
can be coded as <
; and >
can be coded as >
; in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses <
and >
as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they’ve been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
Type | Origin | Description |
---|---|---|
Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user’s browser. |
DOM-based | Client | The attacker forces the user’s browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
How to prevent
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?
,&
,/
,<
,>
and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Remediation
Upgrade serialize-javascript
to version 6.0.2 or higher.
References
medium severity
- Vulnerable module: node-fetch
- Introduced through: isomorphic-fetch@2.2.1 and glamor@2.20.40
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › isomorphic-fetch@2.2.1 › node-fetch@1.7.3Remediation: Upgrade to isomorphic-fetch@3.0.0.
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › glamor@2.20.40 › fbjs@0.8.18 › isomorphic-fetch@2.2.1 › node-fetch@1.7.3
Overview
node-fetch is a light-weight module that brings window.fetch to node.js
Affected versions of this package are vulnerable to Denial of Service. Node Fetch did not honor the size
option after following a redirect, which means that when a content size was over the limit, a FetchError would never get thrown and the process would end without failure.
Remediation
Upgrade node-fetch
to version 2.6.1, 3.0.0-beta.9 or higher.
References
medium severity
- Vulnerable module: immer
- Introduced through: error-overlay-webpack-plugin@0.1.7
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › immer@1.10.0Remediation: Upgrade to error-overlay-webpack-plugin@1.1.0.
Overview
immer is a package that allows you to create your next immutable state by mutating the current one.
Affected versions of this package are vulnerable to Prototype Pollution. A type confusion vulnerability can lead to a bypass of CVE-2020-28477 when the user-provided keys used in the path
parameter are arrays. In particular, this bypass is possible because the condition (p === "__proto__" || p === "constructor")
in applyPatches_
returns false
if p
is ['__proto__']
(or ['constructor']
). The ===
operator (strict equality operator) returns false
if the operands have different type.
PoC
const {applyPatches, enablePatches} = require("immer");
enablePatches();
// applyPatches({}, [ { op: 'add', path: [ "__proto__", "polluted" ], value: "yes" } ]);
// applyPatches({}, [ { op: 'replace', path: [ "__proto__", "polluted" ], value: "yes" } ]);
// console.log(polluted); // Error: [Immer] Patching reserved attributes like __proto__, prototype and constructor is not allowed
applyPatches({}, [ { op: 'add', path: [['__proto__'], 'polluted'], value: 'yes' } ]);
// applyPatches({}, [ { op: 'replace', path: [['__proto__'], 'polluted'], value: 'yes' } ]);
console.log(polluted);
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 mergeProperty 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
Web browser
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 immer
to version 9.0.6 or higher.
References
medium severity
- Vulnerable module: node-forge
- Introduced through: webpack-dev-server@3.11.3
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › selfsigned@1.10.14 › node-forge@0.10.0Remediation: Upgrade to webpack-dev-server@4.7.3.
Overview
node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.
Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature due to RSA's PKCS#1 v1.5
signature verification code which does not properly check DigestInfo
for a proper ASN.1
structure. This can lead to successful verification with signatures that contain invalid structures but a valid digest.
Remediation
Upgrade node-forge
to version 1.3.0 or higher.
References
medium severity
- Vulnerable module: node-forge
- Introduced through: webpack-dev-server@3.11.3
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › selfsigned@1.10.14 › node-forge@0.10.0Remediation: Upgrade to webpack-dev-server@4.7.3.
Overview
node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.
Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature due to RSAs
PKCS#1` v1.5 signature verification code which is lenient in checking the digest algorithm structure. This can allow a crafted structure that steals padding bytes and uses unchecked portion of the PKCS#1 encoded message to forge a signature when a low public exponent is being used.
Remediation
Upgrade node-forge
to version 1.3.0 or higher.
References
medium severity
- Vulnerable module: react-dev-utils
- Introduced through: error-overlay-webpack-plugin@0.1.7 and react-dev-utils@5.0.2
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0Remediation: Upgrade to error-overlay-webpack-plugin@0.4.2.
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › react-dev-utils@5.0.2Remediation: Upgrade to react-dev-utils@11.0.4.
Overview
react-dev-utils is an includes some utilities used by Create React App.
Affected versions of this package are vulnerable to Command Injection via getProcessForPort
- where an input argument is concatenated into a command string to be executed. This function is typically used from react-scripts (in Create React App projects), where the usage is safe. Only when this function is manually invoked with user-provided values (ie: by custom code) is there the potential for command injection. If you're consuming it from react-scripts then this issue does not affect you.
Remediation
Upgrade react-dev-utils
to version 11.0.4 or higher.
References
medium severity
- Vulnerable module: @hapi/statehood
- Introduced through: @hapi/hapi@18.4.0
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › @hapi/hapi@18.4.0 › @hapi/statehood@6.1.2Remediation: Upgrade to @hapi/hapi@19.0.0.
Overview
@hapi/statehood is a HTTP State Management Utilities package.
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via the cookie parser due to improper regex usage.
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 @hapi/statehood
to version 7.0.4 or higher.
References
medium severity
- Vulnerable module: browserslist
- Introduced through: error-overlay-webpack-plugin@0.1.7
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › browserslist@4.4.1Remediation: Upgrade to error-overlay-webpack-plugin@1.1.0.
Overview
browserslist is a Share target browsers between different front-end tools, like Autoprefixer, Stylelint and babel-env-preset
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) during parsing of queries.
PoC by Yeting Li
var browserslist = require("browserslist")
function build_attack(n) {
var ret = "> "
for (var i = 0; i < n; i++) {
ret += "1"
}
return ret + "!";
}
// browserslist('> 1%')
//browserslist(build_attack(500000))
for(var i = 1; i <= 500000; i++) {
if (i % 1000 == 0) {
var time = Date.now();
var attack_str = build_attack(i)
try{
browserslist(attack_str);
var time_cost = Date.now() - time;
console.log("attack_str.length: " + attack_str.length + ": " + time_cost+" ms");
}
catch(e){
var time_cost = Date.now() - time;
console.log("attack_str.length: " + attack_str.length + ": " + time_cost+" ms");
}
}
}
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 browserslist
to version 4.16.5 or higher.
References
medium severity
- Vulnerable module: glob-parent
- Introduced through: webpack-dev-server@3.11.3, error-overlay-webpack-plugin@0.1.7 and others
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › chokidar@2.1.8 › glob-parent@3.1.0Remediation: Upgrade to webpack-dev-server@4.0.0.
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › fork-ts-checker-webpack-plugin@1.0.0-alpha.6 › chokidar@2.1.8 › glob-parent@3.1.0Remediation: Upgrade to error-overlay-webpack-plugin@1.1.0.
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack@4.47.0 › watchpack@1.7.5 › watchpack-chokidar2@2.0.1 › chokidar@2.1.8 › glob-parent@3.1.0
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › globby@8.0.2 › fast-glob@2.2.7 › glob-parent@3.1.0Remediation: Upgrade to error-overlay-webpack-plugin@0.4.2.
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: loader-utils
- Introduced through: error-overlay-webpack-plugin@0.1.7
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › loader-utils@1.2.3Remediation: Upgrade to error-overlay-webpack-plugin@1.1.0.
Overview
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via the resourcePath
variable in interpolateName.js
.
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 loader-utils
to version 1.4.2, 2.0.4, 3.2.1 or higher.
References
medium severity
- Vulnerable module: loader-utils
- Introduced through: error-overlay-webpack-plugin@0.1.7
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › loader-utils@1.2.3Remediation: Upgrade to error-overlay-webpack-plugin@1.1.0.
Overview
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) in interpolateName
function via the URL
variable.
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 loader-utils
to version 1.4.2, 2.0.4, 3.2.1 or higher.
References
medium severity
- Vulnerable module: lodash
- Introduced through: assets-webpack-plugin@3.10.0
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › assets-webpack-plugin@3.10.0 › lodash@4.17.15Remediation: Upgrade to assets-webpack-plugin@4.0.0.
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: minimatch
- Introduced through: error-overlay-webpack-plugin@0.1.7 and react-dev-utils@5.0.2
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › error-overlay-webpack-plugin@0.1.7 › react-dev-utils@8.0.0 › recursive-readdir@2.2.2 › minimatch@3.0.4Remediation: Upgrade to error-overlay-webpack-plugin@1.1.0.
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › react-dev-utils@5.0.2 › recursive-readdir@2.2.1 › minimatch@3.0.3Remediation: Upgrade to react-dev-utils@12.0.0.
Overview
minimatch is a minimal matching utility.
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via the braceExpand
function in minimatch.js
.
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 3.0.5 or higher.
References
medium severity
- Vulnerable module: node-forge
- Introduced through: webpack-dev-server@3.11.3
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › webpack-dev-server@3.11.3 › selfsigned@1.10.14 › node-forge@0.10.0Remediation: Upgrade to webpack-dev-server@4.7.3.
Overview
node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.
Affected versions of this package are vulnerable to Open Redirect via parseUrl
function when it mishandles certain uses of backslash such as https:/\/\/\
and interprets the URI as a relative path.
PoC:
// poc.js
var forge = require("node-forge");
var url = forge.util.parseUrl("https:/\/\/\www.github.com/foo/bar");
console.log(url);
// Output of node poc.js:
{
full: 'https://',
scheme: 'https',
host: '',
port: 443,
path: '/www.github.com/foo/bar', <<<---- path should be "/foo/bar"
fullHost: ''
}
Remediation
Upgrade node-forge
to version 1.0.0 or higher.
References
medium severity
- Vulnerable module: redis
- Introduced through: cache-manager-redis-store@1.5.0
Detailed paths
-
Introduced through: tapestry-lite@shortlist-digital/tapestry-lite#1e75537ab6ab835f60f8197cb7521afe82b53da6 › cache-manager-redis-store@1.5.0 › redis@2.8.0Remediation: Upgrade to cache-manager-redis-store@2.0.0.
Overview
redis is an A high performance Redis client.
Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS). When a client is in monitoring mode, monitor_regex
, which is used to detected monitor messages` could cause exponential backtracking on some strings, leading to denial of service.
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 redis
to version 3.1.1 or higher.