Vulnerabilities

28 via 44 paths

Dependencies

499

Source

GitHub

Commit

1a404ea1

Find, fix and prevent vulnerabilities in your code.

Severity
  • 11
  • 17
Status
  • 28
  • 0
  • 0

high severity

Server-side Request Forgery (SSRF)

  • Vulnerable module: ip
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 proxy-agent@3.1.1 socks-proxy-agent@4.0.2 socks@2.3.3 ip@1.1.5
    Remediation: Upgrade to snyk@1.518.0.
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 proxy-agent@3.1.1 pac-proxy-agent@3.0.1 socks-proxy-agent@4.0.2 socks@2.3.3 ip@1.1.5
    Remediation: Upgrade to snyk@1.518.0.

Overview

ip is a Node library.

Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF) via the isPublic function, by failing to identify hex-encoded 0x7f.1 as equivalent to the private addess 127.0.0.1. An attacker can expose sensitive information, interact with internal services, or exploit other vulnerabilities within the network by exploiting this vulnerability.

PoC

var ip = require('ip');

console.log(ip.isPublic("0x7f.1"));
//This returns true. It should be false because 0x7f.1 == 127.0.0.1 == 0177.1

Remediation

Upgrade ip to version 1.1.9, 2.0.1 or higher.

References

high severity

Remote Code Execution (RCE)

  • Vulnerable module: pac-resolver
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 proxy-agent@3.1.1 pac-proxy-agent@3.0.1 pac-resolver@3.0.0
    Remediation: Upgrade to snyk@1.518.0.

Overview

Affected versions of this package are vulnerable to Remote Code Execution (RCE). This can occur when used with untrusted input, due to unsafe PAC file handling.

In order to exploit this vulnerability in practice, this either requires an attacker on your local network, a specific vulnerable configuration, or some second vulnerability that allows an attacker to set your config values.

NOTE: The fix for this vulnerability is applied in the node-degenerator library, a dependency is written by the same maintainer.

PoC

const pac = require('pac-resolver');

// Should keep running forever (if not vulnerable):
setInterval(() => {
    console.log("Still running");
}, 1000);

// Parsing a malicious PAC file unexpectedly executes unsandboxed code:
pac(`
    // Real PAC config:
    function FindProxyForURL(url, host) {
        return "DIRECT";
    }

    // But also run arbitrary code:
    var f = this.constructor.constructor(\`
        // Running outside the sandbox:
        console.log('Read env vars:', process.env);
        console.log('!!! PAC file is running arbitrary code !!!');
        console.log('Can read & could exfiltrate env vars ^');
        console.log('Can kill parsing process, like so:');
        process.exit(100); // Kill the vulnerable process
        // etc etc
    \`);

    f();

Remediation

Upgrade pac-resolver to version 5.0.0 or higher.

References

high severity

Server-side Request Forgery (SSRF)

  • Vulnerable module: netmask
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 proxy-agent@3.1.1 pac-proxy-agent@3.0.1 pac-resolver@3.0.0 netmask@1.0.6
    Remediation: Upgrade to snyk@1.518.0.

Overview

netmask is a library to parse IPv4 CIDR blocks.

Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF). It incorrectly evaluates individual IPv4 octets that contain octal strings as left-stripped integers, leading to an inordinate attack surface on hundreds of thousands of projects that rely on netmask to filter or evaluate IPv4 block ranges, both inbound and outbound.

For example, a remote unauthenticated attacker can request local resources using input data 0177.0.0.1 (127.0.0.1), which netmask evaluates as the public IP 177.0.0.1. Contrastingly, a remote authenticated or unauthenticated attacker can input the data 0127.0.0.01 (87.0.0.1) as localhost, yet the input data is a public IP and can potentially cause local and remote file inclusion (LFI/RFI). A remote authenticated or unauthenticated attacker can bypass packages that rely on netmask to filter IP address blocks to reach intranets, VPNs, containers, adjacent VPC instances, or LAN hosts, using input data such as 012.0.0.1 (10.0.0.1), which netmask evaluates as 12.0.0.1 (public).

NOTE: This vulnerability has also been identified as: CVE-2021-29418

Remediation

Upgrade netmask to version 2.0.1 or higher.

References

high severity

Server-side Request Forgery (SSRF)

  • Vulnerable module: netmask
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 proxy-agent@3.1.1 pac-proxy-agent@3.0.1 pac-resolver@3.0.0 netmask@1.0.6
    Remediation: Upgrade to snyk@1.518.0.

Overview

netmask is a library to parse IPv4 CIDR blocks.

Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF). It incorrectly evaluates individual IPv4 octets that contain octal strings as left-stripped integers, leading to an inordinate attack surface on hundreds of thousands of projects that rely on netmask to filter or evaluate IPv4 block ranges, both inbound and outbound.

For example, a remote unauthenticated attacker can request local resources using input data 0177.0.0.1 (127.0.0.1), which netmask evaluates as the public IP 177.0.0.1. Contrastingly, a remote authenticated or unauthenticated attacker can input the data 0127.0.0.01 (87.0.0.1) as localhost, yet the input data is a public IP and can potentially cause local and remote file inclusion (LFI/RFI). A remote authenticated or unauthenticated attacker can bypass packages that rely on netmask to filter IP address blocks to reach intranets, VPNs, containers, adjacent VPC instances, or LAN hosts, using input data such as 012.0.0.1 (10.0.0.1), which netmask evaluates as 12.0.0.1 (public).

NOTE: This vulnerability has also been identified as: CVE-2021-28918

Remediation

Upgrade netmask to version 2.0.1 or higher.

References

high severity

Prototype Pollution

  • Vulnerable module: i18next
  • Introduced through: i18next@19.8.4

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 i18next@19.8.4
    Remediation: Upgrade to i18next@19.8.5.

Overview

i18next is an internationalization framework for browser or any other javascript environment (eg. node.js).

Affected versions of this package are vulnerable to Prototype Pollution via getLastOfPath() in i18next.js.

Details

Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as __proto__, constructor and prototype. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.

There are two main ways in which the pollution of prototypes occurs:

  • Unsafe Object recursive merge

  • Property definition by path

Unsafe Object recursive merge

The logic of a vulnerable recursive merge function follows the following high-level model:

merge (target, source)

  foreach property of source

    if property exists and is an object on both the target and the source

      merge(target[property], source[property])

    else

      target[property] = source[property]

When the source object contains a property named __proto__ defined with Object.defineProperty() , the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object and the source of Object as defined by the attacker. Properties are then copied on the Object prototype.

Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source).

lodash and Hoek are examples of libraries susceptible to recursive merge attacks.

Property definition by path

There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)

If the attacker can control the value of “path”, they can set this value to __proto__.myValue. myValue is then assigned to the prototype of the class of the object.

Types of attacks

There are a few methods by which Prototype Pollution can be manipulated:

Type Origin Short description
Denial of service (DoS) Client This is the most likely attack.
DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf).
The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object. In this case, the code fails and is likely to cause a denial of service.
For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail.
Remote Code Execution Client Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation.
For example: eval(someobject.someattr). In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code.
Property Injection Client The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens.
For example: if a codebase checks privileges for someuser.isAdmin, then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true, they can then achieve admin privileges.

Affected environments

The following environments are susceptible to a Prototype Pollution attack:

  • Application server

  • Web server

  • Web browser

How to prevent

  1. Freeze the prototype— use Object.freeze (Object.prototype).

  2. Require schema validation of JSON input.

  3. Avoid using unsafe recursive merge functions.

  4. Consider using objects without prototypes (for example, Object.create(null)), breaking the prototype chain and preventing pollution.

  5. As a best practice use Map instead of Object.

For more information on this vulnerability type:

Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018

Remediation

Upgrade i18next to version 19.8.5 or higher.

References

high severity

Infinite loop

  • Vulnerable module: markdown-it
  • Introduced through: jsdoc-to-markdown@6.0.1

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 jsdoc-to-markdown@6.0.1 jsdoc-api@6.0.0 jsdoc@3.6.11 markdown-it@12.3.2

Overview

markdown-it is a modern pluggable markdown parser.

Affected versions of this package are vulnerable to Infinite loop in linkify inline rule when using malformed input.

Remediation

Upgrade markdown-it to version 13.0.2 or higher.

References

high severity

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: marked
  • Introduced through: jsdoc-to-markdown@6.0.1

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 jsdoc-to-markdown@6.0.1 dmd@5.0.2 marked@1.2.9
    Remediation: Upgrade to jsdoc-to-markdown@7.0.0.

Overview

marked is a low-level compiler for parsing markdown without caching or blocking for long periods of time.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS). 3 or more groups of odd and even numbered consecutive underscores (___) followed by a character causes extended processing.

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:

  1. CCC
  2. CC+C
  3. C+CC
  4. 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 marked to version 2.0.0 or higher.

References

high severity

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: parse-link-header
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-docker-plugin@4.13.1 @snyk/snyk-docker-pull@3.2.3 @snyk/docker-registry-v2-client@1.13.9 parse-link-header@1.0.1
    Remediation: Upgrade to snyk@1.611.0.

Overview

parse-link-header is a package that parses a link header and returns paging information for each contained link.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via the checkHeader function.

PoC

var parse = require('parse-link-header');
const {performance} = require('perf_hooks');

function payload (n) {
var ret = ""
for (var i = 0; i < n; i++) {
ret += " "
}
return ret
}

var linkHeader = '; rel="' + payload(10000) + '",'

t = performance.now()
var parsed = parse(linkHeader);
console.log(performance.now() - t)

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:

  1. CCC
  2. CC+C
  3. C+CC
  4. 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 parse-link-header to version 2.0.0 or higher.

References

high severity

Command Injection

  • Vulnerable module: ssh2
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-docker-plugin@4.13.1 docker-modem@2.1.3 ssh2@0.8.9
    Remediation: Upgrade to snyk@1.685.0.

Overview

ssh2 is a SSH2 client and server modules written in pure JavaScript for node.js.

Affected versions of this package are vulnerable to Command Injection. The issue only exists on Windows. This issue may lead to remote code execution if a client of the library calls the vulnerable method with untrusted input.

Remediation

Upgrade ssh2 to version 1.0.0 or higher.

References

high severity

Internal Property Tampering

  • Vulnerable module: taffydb
  • Introduced through: jsdoc-to-markdown@6.0.1

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 jsdoc-to-markdown@6.0.1 jsdoc-api@6.0.0 jsdoc@3.6.11 taffydb@2.6.2

Overview

taffydb is an open source JavaScript library that provides in-memory database capabilities

Affected versions of this package are vulnerable to Internal Property Tampering. taffy sets an internal index for each data item in its DB. However, it is found that the internal index can be forged by adding additional properties into user-input. If an index is found in the query, taffyDB will ignore other query conditions and directly return the indexed data item. Moreover, the internal index is in an easily-guessable format (e.g. T000002R000001). As such, attackers can use this vulnerability to access any data items in the DB and exploit an SQL Injection.

Note: The taffy package has been deprecated by the author. Its successor package, taffydb, is also found to be vulnerable and is not actively maintained.

PoC

var TAFFY = require('taffy');
var friends = TAFFY([
        {"id":1,"gender":"M","username":"Smith","password":"aaa","status":"Active"},
        {"id":2,"gender":"F","username":"Ruth","password":"bbb","status":"Active"},
        {"id":3,"gender":"M","username":"Stevenson","password":"ccc","status":"Active"},
        {"id":4,"gender":"F","username":"Gill","password":"ddd","status":"Active"}
]);

var json = {username:"Smith", "password":"123", "___id":"T000002R000002", "___s":true};
var item1 = friends(json);
console.log(item1.first());

Remediation

There is no fixed version for taffydb.

References

high severity

Prototype Pollution

  • Vulnerable module: lodash.set
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-nodejs-lockfile-parser@1.30.1 lodash.set@4.3.2
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-resolve-deps@4.4.0 lodash.set@4.3.2
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-docker-plugin@4.13.1 snyk-nodejs-lockfile-parser@1.30.1 lodash.set@4.3.2
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-nuget-plugin@1.19.4 dotnet-deps-parser@5.0.0 lodash.set@4.3.2

Overview

lodash.set is a lodash method _.set exported as a Node.js module.

Affected versions of this package are vulnerable to Prototype Pollution via the set and setwith functions due to improper user input sanitization.

Note

lodash.set is not maintained for a long time. It is recommended to use lodash library, which contains the fix since version 4.17.17.

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 merge

  • Property definition by path

Unsafe Object recursive merge

The logic of a vulnerable recursive merge function follows the following high-level model:

merge (target, source)

  foreach property of source

    if property exists and is an object on both the target and the source

      merge(target[property], source[property])

    else

      target[property] = source[property]

When the source object contains a property named __proto__ defined with Object.defineProperty() , the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object and the source of Object as defined by the attacker. Properties are then copied on the Object prototype.

Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source).

lodash and Hoek are examples of libraries susceptible to recursive merge attacks.

Property definition by path

There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)

If the attacker can control the value of “path”, they can set this value to __proto__.myValue. myValue is then assigned to the prototype of the class of the object.

Types of attacks

There are a few methods by which Prototype Pollution can be manipulated:

Type Origin Short description
Denial of service (DoS) Client This is the most likely attack.
DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf).
The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object. In this case, the code fails and is likely to cause a denial of service.
For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail.
Remote Code Execution Client Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation.
For example: eval(someobject.someattr). In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code.
Property Injection Client The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens.
For example: if a codebase checks privileges for someuser.isAdmin, then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true, they can then achieve admin privileges.

Affected environments

The following environments are susceptible to a Prototype Pollution attack:

  • Application server

  • Web server

  • Web browser

How to prevent

  1. Freeze the prototype— use Object.freeze (Object.prototype).

  2. Require schema validation of JSON input.

  3. Avoid using unsafe recursive merge functions.

  4. Consider using objects without prototypes (for example, Object.create(null)), breaking the prototype chain and preventing pollution.

  5. As a best practice use Map instead of Object.

For more information on this vulnerability type:

Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018

Remediation

There is no fixed version for lodash.set.

References

medium severity

Command Injection

  • Vulnerable module: snyk
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3
    Remediation: Upgrade to snyk@1.996.0.

Overview

snyk is an advanced tool that scans and monitors projects for security vulnerabilities.

Affected versions of this package are vulnerable to Command Injection via the snyk-go-plugin which is used by the Snyk CLI tool.

A successful exploit, allows attackers to run arbitrary commands on the host system where the Snyk CLI is installed. In order to exploit this vulnerability, a target would have to execute the “snyk test” command on untrusted files. As developers are unlikely to run "snyk test" on untrusted files, an attacker might have to trick them into opening a malicious file before running "snyk test".

Remediation

Upgrade snyk to version 1.996.0 or higher.

References

medium severity

Command Injection

  • Vulnerable module: snyk-go-plugin
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-go-plugin@1.16.4
    Remediation: Upgrade to snyk@1.685.0.

Overview

snyk-go-plugin is a Snyk plugin that provides metadata for Golang projects.

Affected versions of this package are vulnerable to Command Injection via the snyk-go-plugin which is used by the Snyk CLI tool.

A successful exploit, allows attackers to run arbitrary commands on the host system where the Snyk CLI is installed. In order to exploit this vulnerability, a target would have to execute the “snyk test” command on untrusted files. As developers are unlikely to run "snyk test" on untrusted files, an attacker might have to trick them into opening a malicious file before running "snyk test".

Remediation

Upgrade snyk-go-plugin to version 1.19.1 or higher.

References

medium severity

Arbitrary File Write via Archive Extraction (Zip Slip)

  • Vulnerable module: jszip
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-nuget-plugin@1.19.4 jszip@3.4.0
    Remediation: Upgrade to snyk@1.685.0.

Overview

jszip is a Create, read and edit .zip files with JavaScript http://stuartk.com/jszip

Affected versions of this package are vulnerable to Arbitrary File Write via Archive Extraction (Zip Slip) due to improper sanitization of filenames when files are loaded with the loadAsync method.

Details

It is exploited using a specially crafted zip archive, that holds path traversal filenames. When exploited, a filename in a malicious archive is concatenated to the target extraction directory, which results in the final path ending up outside of the target folder. For instance, a zip may hold a file with a "../../file.exe" location and thus break out of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicous file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:


+2018-04-15 22:04:29 ..... 19 19 good.txt

+2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys

Remediation

Upgrade jszip to version 2.7.0, 3.8.0 or higher.

References

medium severity

Missing Release of Resource after Effective Lifetime

  • Vulnerable module: inflight
  • Introduced through: snyk@1.437.3 and jsdoc-to-markdown@6.0.1

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-mvn-plugin@2.25.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 jsdoc-to-markdown@6.0.1 dmd@5.0.2 file-set@4.0.2 glob@7.2.3 inflight@1.0.6
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 jsdoc-to-markdown@6.0.1 jsdoc-api@6.0.0 file-set@4.0.2 glob@7.2.3 inflight@1.0.6
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-gradle-plugin@3.11.0 @snyk/java-call-graph-builder@1.18.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-mvn-plugin@2.25.0 @snyk/java-call-graph-builder@1.17.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-mvn-plugin@2.25.0 tmp@0.1.0 rimraf@2.7.1 glob@7.2.3 inflight@1.0.6
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-sbt-plugin@2.11.0 tmp@0.1.0 rimraf@2.7.1 glob@7.2.3 inflight@1.0.6
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-go-plugin@1.16.4 tmp@0.2.1 rimraf@3.0.2 glob@7.2.3 inflight@1.0.6
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-gradle-plugin@3.11.0 tmp@0.2.1 rimraf@3.0.2 glob@7.2.3 inflight@1.0.6
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-docker-plugin@4.13.1 @snyk/snyk-docker-pull@3.2.3 tmp@0.1.0 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

Code Injection

  • Vulnerable module: snyk
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3
    Remediation: Upgrade to snyk@1.1064.0.

Overview

snyk is a advanced tool that scans and monitors projects for security vulnerabilities.

Affected versions of this package are vulnerable to Code Injection. when analyzing a project. An attacker who can convince a user to scan a malicious project can include commands in a build file such as build.gradle or gradle-wrapper.jar, which will be executed with the privileges of the application.

This vulnerability may be triggered when running the the CLI tool directly, or when running a scan with one of the IDE plugins that invoke the Snyk CLI.

Successful exploitation of this issue would likely require some level of social engineering - to coerce an untrusted project to be downloaded and analyzed via the Snyk CLI or opened in an IDE where a Snyk IDE plugin is installed and enabled. Additionally, if the IDE has a Trust feature then the target folder must be marked as ‘trusted’ in order to be vulnerable.

NOTE: This issue is independent of the one reported in CVE-2022-40764, and upgrading to a fixed version for this addresses that issue as well.

The affected IDE plugins and versions are:

  • VS Code - Affected: <=1.8.0, Fixed: 1.9.0
  • IntelliJ - Affected: <=2.4.47, Fixed: 2.4.48
  • Visual Studio - Affected: <=1.1.30, Fixed: 1.1.31
  • Eclipse - Affected: <=v20221115, Fixed: v20221130
  • Language Server - Affected: <=v20221109, Fixed: v20221130

Remediation

Upgrade snyk to version 1.1064.0 or higher.

References

medium severity

Open Redirect

  • Vulnerable module: got
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-nodejs-lockfile-parser@1.30.1 got@11.4.0
    Remediation: Upgrade to snyk@1.685.0.
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-docker-plugin@4.13.1 snyk-nodejs-lockfile-parser@1.30.1 got@11.4.0
    Remediation: Upgrade to snyk@1.654.0.
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 update-notifier@4.1.3 latest-version@5.1.0 package-json@6.5.0 got@9.6.0
    Remediation: Upgrade to snyk@1.680.0.

Overview

Affected versions of this package are vulnerable to Open Redirect due to missing verification of requested URLs. It allowed a victim to be redirected to a UNIX socket.

Remediation

Upgrade got to version 11.8.5, 12.1.0 or higher.

References

medium severity

Denial of Service (DoS)

  • Vulnerable module: jszip
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-nuget-plugin@1.19.4 jszip@3.4.0
    Remediation: Upgrade to snyk@1.667.0.

Overview

jszip is a Create, read and edit .zip files with JavaScript http://stuartk.com/jszip

Affected versions of this package are vulnerable to Denial of Service (DoS). Crafting a new zip file with filenames set to Object prototype values (e.g __proto__, toString, etc) results in a returned object with a modified prototype instance.

PoC

const jszip = require('jszip');

async function loadZip() {
// this is a raw buffer of demo.zip containing 2 empty files:
// - "file.txt"
// - "toString"
const demoZip = Buffer.from('UEsDBBQACAAIANS8kVIAAAAAAAAAAAAAAAAIACAAdG9TdHJpbmdVVA0AB3Bje2BmY3tgcGN7YHV4CwABBPUBAAAEFAAAAAMAUEsHCAAAAAACAAAAAAAAAFBLAwQUAAgACADDvJFSAAAAAAAAAAAAAAAACAAgAGZpbGUudHh0VVQNAAdPY3tg4FJ7YE9je2B1eAsAAQT1AQAABBQAAAADAFBLBwgAAAAAAgAAAAAAAABQSwECFAMUAAgACADUvJFSAAAAAAIAAAAAAAAACAAgAAAAAAAAAAAApIEAAAAAdG9TdHJpbmdVVA0AB3Bje2BmY3tgcGN7YHV4CwABBPUBAAAEFAAAAFBLAQIUAxQACAAIAMO8kVIAAAAAAgAAAAAAAAAIACAAAAAAAAAAAACkgVgAAABmaWxlLnR4dFVUDQAHT2N7YOBSe2BPY3tgdXgLAAEE9QEAAAQUAAAAUEsFBgAAAAACAAIArAAAALAAAAAAAA==', 'base64');

const zip = await jszip.loadAsync(demoZip);
zip.files.toString(); // this will throw
return zip;
}
loadZip();

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

  • High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

  • Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade jszip to version 3.7.0 or higher.

References

medium severity

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: marked
  • Introduced through: jsdoc-to-markdown@6.0.1

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 jsdoc-to-markdown@6.0.1 dmd@5.0.2 marked@1.2.9
    Remediation: Upgrade to jsdoc-to-markdown@7.0.0.

Overview

marked is a low-level compiler for parsing markdown without caching or blocking for long periods of time.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) when passing unsanitized user input to inline.reflinkSearch, if it is not being parsed by a time-limited worker thread.

PoC

import * as marked from 'marked';

console.log(marked.parse(`[x]: x

\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](`));

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:

  1. CCC
  2. CC+C
  3. C+CC
  4. 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 marked to version 4.0.10 or higher.

References

medium severity

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: marked
  • Introduced through: jsdoc-to-markdown@6.0.1

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 jsdoc-to-markdown@6.0.1 dmd@5.0.2 marked@1.2.9
    Remediation: Upgrade to jsdoc-to-markdown@7.0.0.

Overview

marked is a low-level compiler for parsing markdown without caching or blocking for long periods of time.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) when unsanitized user input is passed to block.def.

PoC

import * as marked from "marked";
marked.parse(`[x]:${' '.repeat(1500)}x ${' '.repeat(1500)} x`);

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:

  1. CCC
  2. CC+C
  3. C+CC
  4. 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 marked to version 4.0.10 or higher.

References

medium severity

Prototype Pollution

  • Vulnerable module: xml2js
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-nuget-plugin@1.19.4 xml2js@0.4.23
    Remediation: Upgrade to snyk@1.685.0.
  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-nuget-plugin@1.19.4 dotnet-deps-parser@5.0.0 xml2js@0.4.23
    Remediation: Upgrade to snyk@1.685.0.

Overview

Affected versions of this package are vulnerable to Prototype Pollution due to allowing an external attacker to edit or add new properties to an object. This is possible because the application does not properly validate incoming JSON keys, thus allowing the __proto__ property to be edited.

PoC

var parseString = require('xml2js').parseString;

let normal_user_request    = "<role>admin</role>";
let malicious_user_request = "<__proto__><role>admin</role></__proto__>";

const update_user = (userProp) => {
    // A user cannot alter his role. This way we prevent privilege escalations.
    parseString(userProp, function (err, user) {
        if(user.hasOwnProperty("role") && user?.role.toLowerCase() === "admin") {
            console.log("Unauthorized Action");
        } else {
            console.log(user?.role[0]);
        }
    });
}

update_user(normal_user_request);
update_user(malicious_user_request);

Details

Prototype Pollution is a vulnerability affecting JavaScript. Prototype Pollution refers to the ability to inject properties into existing JavaScript language construct prototypes, such as objects. JavaScript allows all Object attributes to be altered, including their magical attributes such as __proto__, constructor and prototype. An attacker manipulates these attributes to overwrite, or pollute, a JavaScript application object prototype of the base object by injecting other values. Properties on the Object.prototype are then inherited by all the JavaScript objects through the prototype chain. When that happens, this leads to either denial of service by triggering JavaScript exceptions, or it tampers with the application source code to force the code path that the attacker injects, thereby leading to remote code execution.

There are two main ways in which the pollution of prototypes occurs:

  • Unsafe Object recursive merge

  • Property definition by path

Unsafe Object recursive merge

The logic of a vulnerable recursive merge function follows the following high-level model:

merge (target, source)

  foreach property of source

    if property exists and is an object on both the target and the source

      merge(target[property], source[property])

    else

      target[property] = source[property]

When the source object contains a property named __proto__ defined with Object.defineProperty() , the condition that checks if the property exists and is an object on both the target and the source passes and the merge recurses with the target, being the prototype of Object and the source of Object as defined by the attacker. Properties are then copied on the Object prototype.

Clone operations are a special sub-class of unsafe recursive merges, which occur when a recursive merge is conducted on an empty object: merge({},source).

lodash and Hoek are examples of libraries susceptible to recursive merge attacks.

Property definition by path

There are a few JavaScript libraries that use an API to define property values on an object based on a given path. The function that is generally affected contains this signature: theFunction(object, path, value)

If the attacker can control the value of “path”, they can set this value to __proto__.myValue. myValue is then assigned to the prototype of the class of the object.

Types of attacks

There are a few methods by which Prototype Pollution can be manipulated:

Type Origin Short description
Denial of service (DoS) Client This is the most likely attack.
DoS occurs when Object holds generic functions that are implicitly called for various operations (for example, toString and valueOf).
The attacker pollutes Object.prototype.someattr and alters its state to an unexpected value such as Int or Object. In this case, the code fails and is likely to cause a denial of service.
For example: if an attacker pollutes Object.prototype.toString by defining it as an integer, if the codebase at any point was reliant on someobject.toString() it would fail.
Remote Code Execution Client Remote code execution is generally only possible in cases where the codebase evaluates a specific attribute of an object, and then executes that evaluation.
For example: eval(someobject.someattr). In this case, if the attacker pollutes Object.prototype.someattr they are likely to be able to leverage this in order to execute code.
Property Injection Client The attacker pollutes properties that the codebase relies on for their informative value, including security properties such as cookies or tokens.
For example: if a codebase checks privileges for someuser.isAdmin, then when the attacker pollutes Object.prototype.isAdmin and sets it to equal true, they can then achieve admin privileges.

Affected environments

The following environments are susceptible to a Prototype Pollution attack:

  • Application server

  • Web server

  • Web browser

How to prevent

  1. Freeze the prototype— use Object.freeze (Object.prototype).

  2. Require schema validation of JSON input.

  3. Avoid using unsafe recursive merge functions.

  4. Consider using objects without prototypes (for example, Object.create(null)), breaking the prototype chain and preventing pollution.

  5. As a best practice use Map instead of Object.

For more information on this vulnerability type:

Arteau, Oliver. “JavaScript prototype pollution attack in NodeJS application.” GitHub, 26 May 2018

Remediation

Upgrade xml2js to version 0.5.0 or higher.

References

medium severity

Command Injection

  • Vulnerable module: @snyk/snyk-cocoapods-plugin
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 @snyk/snyk-cocoapods-plugin@2.5.1
    Remediation: Upgrade to snyk@1.685.0.

Overview

Affected versions of this package are vulnerable to Command Injection due to an incomplete fix for CVE-2022-40764.

A successful exploit allows attackers to run arbitrary commands on the host system where the Snyk CLI is installed by passing in crafted command line flags.

In order to exploit this vulnerability, a user would have to execute the snyk test command on untrusted files. In most cases, an attacker positioned to control the command line arguments to the Snyk CLI would already be positioned to execute arbitrary commands. However, this could be abused in specific scenarios, such as continuous integration pipelines, where developers can control the arguments passed to the Snyk CLI to leverage this component as part of a wider attack against an integration/build pipeline.

This issue has been addressed in the latest Snyk Docker images available at https://hub.docker.com/r/snyk/snyk as of 2022-11-29. Images downloaded and built prior to that date should be updated.

The issue has also been addressed in the Snyk TeamCity CI/CD plugin as of version v20221130.093605.

Remediation

Upgrade @snyk/snyk-cocoapods-plugin to version 2.5.3 or higher.

References

medium severity

Command Injection

  • Vulnerable module: snyk
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3
    Remediation: Upgrade to snyk@1.1064.0.

Overview

snyk is an advanced tool that scans and monitors projects for security vulnerabilities.

Affected versions of this package are vulnerable to Command Injection due to an incomplete fix for CVE-2022-40764.

A successful exploit allows attackers to run arbitrary commands on the host system where the Snyk CLI is installed by passing in crafted command line flags.

In order to exploit this vulnerability, a user would have to execute the snyk test command on untrusted files. In most cases, an attacker positioned to control the command line arguments to the Snyk CLI would already be positioned to execute arbitrary commands. However, this could be abused in specific scenarios, such as continuous integration pipelines, where developers can control the arguments passed to the Snyk CLI to leverage this component as part of a wider attack against an integration/build pipeline.

This issue has been addressed in the latest Snyk Docker images available at https://hub.docker.com/r/snyk/snyk as of 2022-11-29. Images downloaded and built prior to that date should be updated.

The issue has also been addressed in the Snyk TeamCity CI/CD plugin as of version v20221130.093605.

Remediation

Upgrade snyk to version 1.1064.0 or higher.

References

medium severity

Command Injection

  • Vulnerable module: snyk-docker-plugin
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-docker-plugin@4.13.1
    Remediation: Upgrade to snyk@1.685.0.

Overview

Affected versions of this package are vulnerable to Command Injection due to an incomplete fix for CVE-2022-40764.

A successful exploit allows attackers to run arbitrary commands on the host system where the Snyk CLI is installed by passing in crafted command line flags.

In order to exploit this vulnerability, a user would have to execute the snyk test command on untrusted files. In most cases, an attacker positioned to control the command line arguments to the Snyk CLI would already be positioned to execute arbitrary commands. However, this could be abused in specific scenarios, such as continuous integration pipelines, where developers can control the arguments passed to the Snyk CLI to leverage this component as part of a wider attack against an integration/build pipeline.

This issue has been addressed in the latest Snyk Docker images available at https://hub.docker.com/r/snyk/snyk as of 2022-11-29. Images downloaded and built prior to that date should be updated.

The issue has also been addressed in the Snyk TeamCity CI/CD plugin as of version v20221130.093605.

Remediation

Upgrade snyk-docker-plugin to version 5.6.5 or higher.

References

medium severity

Command Injection

  • Vulnerable module: snyk-gradle-plugin
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-gradle-plugin@3.11.0
    Remediation: Upgrade to snyk@1.685.0.

Overview

snyk-gradle-plugin is a plugin for the Snyk CLI tool, providing dependency metadata for Gradle projects.

Affected versions of this package are vulnerable to Command Injection due to an incomplete fix for CVE-2022-40764.

A successful exploit allows attackers to run arbitrary commands on the host system where the Snyk CLI is installed by passing in crafted command line flags.

In order to exploit this vulnerability, a user would have to execute the snyk test command on untrusted files. In most cases, an attacker positioned to control the command line arguments to the Snyk CLI would already be positioned to execute arbitrary commands. However, this could be abused in specific scenarios, such as continuous integration pipelines, where developers can control the arguments passed to the Snyk CLI to leverage this component as part of a wider attack against an integration/build pipeline.

This issue has been addressed in the latest Snyk Docker images available at https://hub.docker.com/r/snyk/snyk as of 2022-11-29. Images downloaded and built prior to that date should be updated.

The issue has also been addressed in the Snyk TeamCity CI/CD plugin as of version v20221130.093605.

Remediation

Upgrade snyk-gradle-plugin to version 3.24.5 or higher.

References

medium severity

Command Injection

  • Vulnerable module: snyk-mvn-plugin
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-mvn-plugin@2.25.0
    Remediation: Upgrade to snyk@1.685.0.

Overview

snyk-mvn-plugin is a plugin for the Snyk CLI tool, providing dependency metadata for Maven projects that use mvn and have a pom.xml file.

Affected versions of this package are vulnerable to Command Injection due to an incomplete fix for CVE-2022-40764.

A successful exploit allows attackers to run arbitrary commands on the host system where the Snyk CLI is installed by passing in crafted command line flags.

In order to exploit this vulnerability, a user would have to execute the snyk test command on untrusted files. In most cases, an attacker positioned to control the command line arguments to the Snyk CLI would already be positioned to execute arbitrary commands. However, this could be abused in specific scenarios, such as continuous integration pipelines, where developers can control the arguments passed to the Snyk CLI to leverage this component as part of a wider attack against an integration/build pipeline.

This issue has been addressed in the latest Snyk Docker images available at https://hub.docker.com/r/snyk/snyk as of 2022-11-29. Images downloaded and built prior to that date should be updated.

The issue has also been addressed in the Snyk TeamCity CI/CD plugin as of version v20221130.093605.

Remediation

Upgrade snyk-mvn-plugin to version 2.31.3 or higher.

References

medium severity

Command Injection

  • Vulnerable module: snyk-python-plugin
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-python-plugin@1.19.1
    Remediation: Upgrade to snyk@1.685.0.

Overview

Affected versions of this package are vulnerable to Command Injection due to an incomplete fix for CVE-2022-40764.

A successful exploit allows attackers to run arbitrary commands on the host system where the Snyk CLI is installed by passing in crafted command line flags.

In order to exploit this vulnerability, a user would have to execute the snyk test command on untrusted files. In most cases, an attacker positioned to control the command line arguments to the Snyk CLI would already be positioned to execute arbitrary commands. However, this could be abused in specific scenarios, such as continuous integration pipelines, where developers can control the arguments passed to the Snyk CLI to leverage this component as part of a wider attack against an integration/build pipeline.

This issue has been addressed in the latest Snyk Docker images available at https://hub.docker.com/r/snyk/snyk as of 2022-11-29. Images downloaded and built prior to that date should be updated.

The issue has also been addressed in the Snyk TeamCity CI/CD plugin as of version v20221130.093605.

Remediation

Upgrade snyk-python-plugin to version 1.24.2 or higher.

References

medium severity

Command Injection

  • Vulnerable module: snyk-sbt-plugin
  • Introduced through: snyk@1.437.3

Detailed paths

  • Introduced through: randomwinpicker@dargmuesli/randomwinpicker#1a404ea15b28aba40314fd7dcad2a97fd103cae7 snyk@1.437.3 snyk-sbt-plugin@2.11.0
    Remediation: Upgrade to snyk@1.685.0.

Overview

Affected versions of this package are vulnerable to Command Injection due to an incomplete fix for CVE-2022-40764.

A successful exploit allows attackers to run arbitrary commands on the host system where the Snyk CLI is installed by passing in crafted command line flags.

In order to exploit this vulnerability, a user would have to execute the snyk test command on untrusted files. In most cases, an attacker positioned to control the command line arguments to the Snyk CLI would already be positioned to execute arbitrary commands. However, this could be abused in specific scenarios, such as continuous integration pipelines, where developers can control the arguments passed to the Snyk CLI to leverage this component as part of a wider attack against an integration/build pipeline.

This issue has been addressed in the latest Snyk Docker images available at https://hub.docker.com/r/snyk/snyk as of 2022-11-29. Images downloaded and built prior to that date should be updated.

The issue has also been addressed in the Snyk TeamCity CI/CD plugin as of version v20221130.093605.

Remediation

Upgrade snyk-sbt-plugin to version 2.16.2 or higher.

References