Vulnerabilities

12 via 28 paths

Dependencies

279

Source

GitHub

Commit

0c12b456

Find, fix and prevent vulnerabilities in your code.

Severity
  • 2
  • 9
  • 1
Status
  • 12
  • 0
  • 0

high severity

Arbitrary Code Execution

  • Vulnerable module: jsen
  • Introduced through: @salesforce/core@1.3.3 and @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 jsen@0.6.6
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 jsen@0.6.6

Overview

jsen is a JSON-Schema validator built for speed

Affected versions of this package are vulnerable to Arbitrary Code Execution. If an attacker can control the schema file, it could run arbitrary JavaScript code on the victim machine. In the module description and README file there is no mention about the risks of untrusted schema files, so I assume that this is applicable.

In particular the required field of the schema is not properly sanitized. The resulting string that is build based on the schema definition is then passed to a Function.apply();, leading to an Arbitrary Code Execution.

PoC

const jsen = require('jsen');

let schema = JSON.parse(`
{
    "type": "object",
    "properties": {
        "username": {
            "type": "string"
        }
    },
    "required": ["\\"+process.mainModule.require(\'child_process\').execSync(\'touch malicious\')+\\""]
}`);

const validate = jsen(schema);
validate({});

Remediation

There is no fixed version for jsen.

References

high severity

Command Injection

  • Vulnerable module: lodash.template
  • Introduced through: @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @oclif/plugin-help@2.2.3 lodash.template@4.5.0

Overview

lodash.template is a The Lodash method _.template exported as a Node.js module.

Affected versions of this package are vulnerable to Command Injection via template.

PoC

var _ = require('lodash');

_.template('', { variable: '){console.log(process.env)}; with(obj' })()

Remediation

There is no fixed version for lodash.template.

References

medium severity

Use of a Broken or Risky Cryptographic Algorithm

  • Vulnerable module: jsonwebtoken
  • Introduced through: @salesforce/core@1.3.3 and @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 jsonwebtoken@8.5.0
    Remediation: Upgrade to @salesforce/core@3.32.12.
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 jsonwebtoken@8.5.0
    Remediation: Upgrade to @salesforce/command@5.0.0.

Overview

jsonwebtoken is a JSON Web Token implementation (symmetric and asymmetric)

Affected versions of this package are vulnerable to Use of a Broken or Risky Cryptographic Algorithm such that the library can be misconfigured to use legacy, insecure key types for signature verification. For example, DSA keys could be used with the RS256 algorithm.

Exploitability

Users are affected when using an algorithm and a key type other than the combinations mentioned below:

EC: ES256, ES384, ES512

RSA: RS256, RS384, RS512, PS256, PS384, PS512

RSA-PSS: PS256, PS384, PS512

And for Elliptic Curve algorithms:

ES256: prime256v1

ES384: secp384r1

ES512: secp521r1

Workaround

Users who are unable to upgrade to the fixed version can use the allowInvalidAsymmetricKeyTypes option to true in the sign() and verify() functions to continue usage of invalid key type/algorithm combination in 9.0.0 for legacy compatibility.

Remediation

Upgrade jsonwebtoken to version 9.0.0 or higher.

References

medium severity

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: csv-parse
  • Introduced through: @salesforce/core@1.3.3 and @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 jsforce@1.8.5 csv-parse@1.3.3
    Remediation: Upgrade to @salesforce/core@2.1.4.
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 jsforce@1.8.5 csv-parse@1.3.3
    Remediation: Upgrade to @salesforce/command@2.0.0.

Overview

csv-parse is a parser converting CSV text input into arrays or objects.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS). The __isInt() function contains a malformed regular expression that processes large specially-crafted input very slowly, leading to a Denial of Service. This is triggered when using the cast option.

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 csv-parse to version 4.4.6 or higher.

References

medium severity

Improper Restriction of Security Token Assignment

  • Vulnerable module: jsonwebtoken
  • Introduced through: @salesforce/core@1.3.3 and @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 jsonwebtoken@8.5.0
    Remediation: Upgrade to @salesforce/core@3.32.12.
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 jsonwebtoken@8.5.0
    Remediation: Upgrade to @salesforce/command@5.0.0.

Overview

jsonwebtoken is a JSON Web Token implementation (symmetric and asymmetric)

Affected versions of this package are vulnerable to Improper Restriction of Security Token Assignment via the secretOrPublicKey argument due to misconfigurations of the key retrieval function jwt.verify(). Exploiting this vulnerability might result in incorrect verification of forged tokens when tokens signed with an asymmetric public key could be verified with a symmetric HS256 algorithm.

Note: This vulnerability affects your application if it supports the usage of both symmetric and asymmetric keys in jwt.verify() implementation with the same key retrieval function.

Remediation

Upgrade jsonwebtoken to version 9.0.0 or higher.

References

medium severity

Server-side Request Forgery (SSRF)

  • Vulnerable module: request
  • Introduced through: @salesforce/core@1.3.3 and @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 jsforce@1.8.5 request@2.88.2
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 jsforce@1.8.5 request@2.88.2

Overview

request is a simplified http request client.

Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF) due to insufficient checks in the lib/redirect.js file by allowing insecure redirects in the default configuration, via an attacker-controller server that does a cross-protocol redirect (HTTP to HTTPS, or HTTPS to HTTP).

NOTE: request package has been deprecated, so a fix is not expected. See https://github.com/request/request/issues/3142.

Remediation

A fix was pushed into the master branch but not yet published.

References

medium severity

Prototype Pollution

  • Vulnerable module: tough-cookie
  • Introduced through: @salesforce/core@1.3.3 and @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 jsforce@1.8.5 request@2.88.2 tough-cookie@2.5.0
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 jsforce@1.8.5 request@2.88.2 tough-cookie@2.5.0
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 sfdx-faye@1.0.9 tough-cookie@2.4.3
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 sfdx-faye@1.0.9 tough-cookie@2.4.3

Overview

tough-cookie is a RFC6265 Cookies and CookieJar module for Node.js.

Affected versions of this package are vulnerable to Prototype Pollution due to improper handling of Cookies when using CookieJar in rejectPublicSuffixes=false mode. Due to an issue with the manner in which the objects are initialized, an attacker can expose or modify a limited amount of property information on those objects. There is no impact to availability.

PoC

// PoC.js
async function main(){
var tough = require("tough-cookie");
var cookiejar = new tough.CookieJar(undefined,{rejectPublicSuffixes:false});
// Exploit cookie
await cookiejar.setCookie(
  "Slonser=polluted; Domain=__proto__; Path=/notauth",
  "https://__proto__/admin"
);
// normal cookie
var cookie = await cookiejar.setCookie(
  "Auth=Lol; Domain=google.com; Path=/notauth",
  "https://google.com/"
);

//Exploit cookie
var a = {};
console.log(a["/notauth"]["Slonser"])
}
main();

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 tough-cookie to version 4.1.3 or higher.

References

medium severity

Improper Authentication

  • Vulnerable module: jsonwebtoken
  • Introduced through: @salesforce/core@1.3.3 and @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 jsonwebtoken@8.5.0
    Remediation: Upgrade to @salesforce/core@3.32.12.
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 jsonwebtoken@8.5.0
    Remediation: Upgrade to @salesforce/command@5.0.0.

Overview

jsonwebtoken is a JSON Web Token implementation (symmetric and asymmetric)

Affected versions of this package are vulnerable to Improper Authentication such that the lack of algorithm definition in the jwt.verify() function can lead to signature validation bypass due to defaulting to the none algorithm for signature verification.

Exploitability

Users are affected only if all of the following conditions are true for the jwt.verify() function:

  1. A token with no signature is received.

  2. No algorithms are specified.

  3. A falsy (e.g., null, false, undefined) secret or key is passed.

Remediation

Upgrade jsonwebtoken to version 9.0.0 or higher.

References

medium severity

Missing Release of Resource after Effective Lifetime

  • Vulnerable module: inflight
  • Introduced through: @salesforce/core@1.3.3 and @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 @salesforce/kit@1.9.2 shx@0.3.4 shelljs@0.8.5 glob@7.2.3 inflight@1.0.6
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/kit@1.9.2 shx@0.3.4 shelljs@0.8.5 glob@7.2.3 inflight@1.0.6
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 bunyan-sfdx-no-dtrace@1.8.2 mv@2.1.1 rimraf@2.4.5 glob@6.0.4 inflight@1.0.6
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 @salesforce/kit@1.9.2 shx@0.3.4 shelljs@0.8.5 glob@7.2.3 inflight@1.0.6
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 bunyan-sfdx-no-dtrace@1.8.2 mv@2.1.1 rimraf@2.4.5 glob@6.0.4 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

Prototype Pollution

  • Vulnerable module: minimist
  • Introduced through: @salesforce/core@1.3.3 and @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 mkdirp@0.5.1 minimist@0.0.8
    Remediation: Upgrade to @salesforce/core@3.24.4.
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 mkdirp@0.5.1 minimist@0.0.8
    Remediation: Upgrade to @salesforce/command@5.0.0.

Overview

minimist is a parse argument options module.

Affected versions of this package are vulnerable to Prototype Pollution. The library could be tricked into adding or modifying properties of Object.prototype using a constructor or __proto__ payload.

PoC by Snyk

require('minimist')('--__proto__.injected0 value0'.split(' '));
console.log(({}).injected0 === 'value0'); // true

require('minimist')('--constructor.prototype.injected1 value1'.split(' '));
console.log(({}).injected1 === 'value1'); // true

Details

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

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

  • Unsafe Object recursive merge

  • Property definition by path

Unsafe Object recursive merge

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

merge (target, source)

  foreach property of source

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

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

    else

      target[property] = source[property]

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

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

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

Property definition by path

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

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

Types of attacks

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

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

Affected environments

The following environments are susceptible to a Prototype Pollution attack:

  • Application server

  • Web server

  • 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 minimist to version 0.2.1, 1.2.3 or higher.

References

medium severity

Prototype Pollution

  • Vulnerable module: xml2js
  • Introduced through: @salesforce/core@1.3.3 and @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 jsforce@1.8.5 xml2js@0.4.23
    Remediation: Upgrade to @salesforce/core@2.15.3.
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 jsforce@1.8.5 xml2js@0.4.23
    Remediation: Upgrade to @salesforce/command@2.0.0.

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

low severity

Prototype Pollution

  • Vulnerable module: minimist
  • Introduced through: @salesforce/core@1.3.3 and @salesforce/command@1.5.3

Detailed paths

  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/core@1.3.3 mkdirp@0.5.1 minimist@0.0.8
    Remediation: Upgrade to @salesforce/core@3.24.4.
  • Introduced through: @mikeburr/sfdx-repl@mburr-salesforce/sfdx-repl#0c12b45653532deeefad94e2ad481595726fd0ef @salesforce/command@1.5.3 @salesforce/core@1.3.3 mkdirp@0.5.1 minimist@0.0.8
    Remediation: Upgrade to @salesforce/command@5.0.0.

Overview

minimist is a parse argument options module.

Affected versions of this package are vulnerable to Prototype Pollution due to a missing handler to Function.prototype.

Notes:

  • This vulnerability is a bypass to CVE-2020-7598

  • The reason for the different CVSS between CVE-2021-44906 to CVE-2020-7598, is that CVE-2020-7598 can pollute objects, while CVE-2021-44906 can pollute only function.

PoC by Snyk

require('minimist')('--_.constructor.constructor.prototype.foo bar'.split(' '));
console.log((function(){}).foo); // bar

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 minimist to version 0.2.4, 1.2.6 or higher.

References