Vulnerabilities

26 via 55 paths

Dependencies

646

Source

GitHub

Commit

c7b3ed27

Find, fix and prevent vulnerabilities in your code.

Severity
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Status
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critical severity

Heap-based Buffer Overflow

  • Vulnerable module: sharp
  • Introduced through: sharp@0.31.3

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef sharp@0.31.3
    Remediation: Upgrade to sharp@0.32.6.

Overview

sharp is a High performance Node.js image processing, the fastest module to resize JPEG, PNG, WebP, GIF, AVIF and TIFF images

Affected versions of this package are vulnerable to Heap-based Buffer Overflow when the ReadHuffmanCodes() function is used. An attacker can craft a special WebP lossless file that triggers the ReadHuffmanCodes() function to allocate the HuffmanCode buffer with a size that comes from an array of precomputed sizes: kTableSize. The color_cache_bits value defines which size to use. The kTableSize array only takes into account sizes for 8-bit first-level table lookups but not second-level table lookups. libwebp allows codes that are up to 15-bit (MAX_ALLOWED_CODE_LENGTH). When BuildHuffmanTable() attempts to fill the second-level tables it may write data out-of-bounds. The OOB write to the undersized array happens in ReplicateValue.

Notes:

This is only exploitable if the color_cache_bits value defines which size to use.

This vulnerability was also published on libwebp CVE-2023-5129

Changelog:

2023-09-12: Initial advisory publication

2023-09-27: Advisory details updated, including CVSS, references

2023-09-27: CVE-2023-5129 rejected as a duplicate of CVE-2023-4863

2023-09-28: Research and addition of additional affected libraries

2024-01-28: Additional fix information

Remediation

Upgrade sharp to version 0.32.6 or higher.

References

critical severity

Uncaught Exception

  • Vulnerable module: multer
  • Introduced through: multer@1.4.4

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef multer@1.4.4
    Remediation: Upgrade to multer@2.0.1.

Overview

Affected versions of this package are vulnerable to Uncaught Exception in makeMiddleware, when processing a file upload request. An attacker can cause the application to crash by sending a request with a field name containing an empty string.

Remediation

Upgrade multer to version 2.0.1 or higher.

References

high severity

Missing Release of Memory after Effective Lifetime

  • Vulnerable module: multer
  • Introduced through: multer@1.4.4

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef multer@1.4.4
    Remediation: Upgrade to multer@2.0.0.

Overview

Affected versions of this package are vulnerable to Missing Release of Memory after Effective Lifetime due to improper handling of error events in HTTP request streams, which fails to close the internal busboy stream. An attacker can cause a denial of service by repeatedly triggering errors in file upload streams, leading to resource exhaustion and memory leaks.

Note:

This is only exploitable if the server is handling file uploads.

Remediation

Upgrade multer to version 2.0.0 or higher.

References

high severity

Uncaught Exception

  • Vulnerable module: multer
  • Introduced through: multer@1.4.4

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef multer@1.4.4
    Remediation: Upgrade to multer@2.0.0.

Overview

Affected versions of this package are vulnerable to Uncaught Exception due to an error event thrown by busboy. An attacker can cause a full nodejs application to crash by sending a specially crafted multi-part upload request.

PoC

const express = require('express')
const multer  = require('multer')
const http  = require('http')
const upload = multer({ dest: 'uploads/' })
const port = 8888

const app = express()

app.post('/upload', upload.single('file'), function (req, res) {
  res.send({})
})

app.listen(port, () => {
  console.log(`Listening on port ${port}`)

  const boundary = 'AaB03x'
  const body = [
    '--' + boundary,
    'Content-Disposition: form-data; name="file"; filename="test.txt"',
    'Content-Type: text/plain',
    '',
    'test without end boundary'
  ].join('\r\n')
  const options = {
    hostname: 'localhost',
    port,
    path: '/upload',
    method: 'POST',
    headers: {
      'content-type': 'multipart/form-data; boundary=' + boundary,
      'content-length': body.length,
    }
  }
  const req = http.request(options, (res) => {
    console.log(res.statusCode)
  })
  req.on('error', (err) => {
    console.error(err)
  })
  req.write(body)
  req.end()
})

Remediation

Upgrade multer to version 2.0.0 or higher.

References

high severity

Uncaught Exception

  • Vulnerable module: multer
  • Introduced through: multer@1.4.4

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef multer@1.4.4
    Remediation: Upgrade to multer@2.0.2.

Overview

Affected versions of this package are vulnerable to Uncaught Exception due to improper handling of multipart requests. An attacker can cause the application to crash by sending a specially crafted malformed multi-part upload request that triggers an unhandled exception.

Remediation

Upgrade multer to version 2.0.2 or higher.

References

high severity

Internal Property Tampering

  • Vulnerable module: bson
  • Introduced through: acl@0.4.11

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef acl@0.4.11 mongodb@2.2.36 mongodb-core@2.1.20 bson@1.0.9

Overview

bson is a BSON Parser for node and browser.

Affected versions of this package are vulnerable to Internal Property Tampering. The package will ignore an unknown value for an object's _bsotype, leading to cases where an object is serialized as a document rather than the intended BSON type.

NOTE: This vulnerability has also been identified as: CVE-2019-2391

Remediation

Upgrade bson to version 1.1.4 or higher.

References

high severity

Internal Property Tampering

  • Vulnerable module: bson
  • Introduced through: acl@0.4.11

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef acl@0.4.11 mongodb@2.2.36 mongodb-core@2.1.20 bson@1.0.9

Overview

bson is a BSON Parser for node and browser.

Affected versions of this package are vulnerable to Internal Property Tampering. The package will ignore an unknown value for an object's _bsotype, leading to cases where an object is serialized as a document rather than the intended BSON type.

NOTE: This vulnerability has also been identified as: CVE-2020-7610

Remediation

Upgrade bson to version 1.1.4 or higher.

References

high severity

Denial of Service (DoS)

  • Vulnerable module: dicer
  • Introduced through: multer@1.4.4

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef multer@1.4.4 busboy@0.2.14 dicer@0.2.5

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS). A malicious attacker can send a modified form to server, and crash the nodejs service. An attacker could sent the payload again and again so that the service continuously crashes.

PoC

await fetch('http://127.0.0.1:8000', { method: 'POST', headers: { ['content-type']: 'multipart/form-data; boundary=----WebKitFormBoundaryoo6vortfDzBsDiro', ['content-length']: '145', connection: 'keep-alive', }, body: '------WebKitFormBoundaryoo6vortfDzBsDiro\r\n Content-Disposition: form-data; name="bildbeschreibung"\r\n\r\n\r\n------WebKitFormBoundaryoo6vortfDzBsDiro--' });

Remediation

There is no fixed version for dicer.

References

high severity

Denial of Service (DoS)

  • Vulnerable module: mongodb
  • Introduced through: acl@0.4.11

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef acl@0.4.11 mongodb@2.2.36

Overview

mongodb is an official MongoDB driver for Node.js.

Affected versions of this package are vulnerable to Denial of Service (DoS). The package fails to properly catch an exception when a collection name is invalid and the DB does not exist, crashing the application.

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 mongodb to version 3.1.13 or higher.

References

high severity

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: semver
  • Introduced through: nodemon@2.0.22

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef nodemon@2.0.22 simple-update-notifier@1.1.0 semver@7.0.0
    Remediation: Upgrade to nodemon@3.0.0.

Overview

semver is a semantic version parser used by npm.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via the function new Range, when untrusted user data is provided as a range.

PoC


const semver = require('semver')
const lengths_2 = [2000, 4000, 8000, 16000, 32000, 64000, 128000]

console.log("n[+] Valid range - Test payloads")
for (let i = 0; i =1.2.3' + ' '.repeat(lengths_2[i]) + '<1.3.0';
const start = Date.now()
semver.validRange(value)
// semver.minVersion(value)
// semver.maxSatisfying(["1.2.3"], value)
// semver.minSatisfying(["1.2.3"], value)
// new semver.Range(value, {})

const end = Date.now();
console.log('length=%d, time=%d ms', value.length, end - start);
}

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 semver to version 5.7.2, 6.3.1, 7.5.2 or higher.

References

high severity

Cross-site Request Forgery (CSRF)

  • Vulnerable module: axios
  • Introduced through: axios@0.27.2

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef axios@0.27.2
    Remediation: Upgrade to axios@0.28.0.

Overview

axios is a promise-based HTTP client for the browser and Node.js.

Affected versions of this package are vulnerable to Cross-site Request Forgery (CSRF) due to inserting the X-XSRF-TOKEN header using the secret XSRF-TOKEN cookie value in all requests to any server when the XSRF-TOKEN0 cookie is available, and the withCredentials setting is turned on. If a malicious user manages to obtain this value, it can potentially lead to the XSRF defence mechanism bypass.

Workaround

Users should change the default XSRF-TOKEN cookie name in the Axios configuration and manually include the corresponding header only in the specific places where it's necessary.

Remediation

Upgrade axios to version 0.28.0, 1.6.0 or higher.

References

medium severity
new

Allocation of Resources Without Limits or Throttling

  • Vulnerable module: axios
  • Introduced through: axios@0.27.2

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef axios@0.27.2
    Remediation: Upgrade to axios@1.12.0.

Overview

axios is a promise-based HTTP client for the browser and Node.js.

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling via the data: URL handler. An attacker can trigger a denial of service by crafting a data: URL with an excessive payload, causing allocation of memory for content decoding before verifying content size limits.

Remediation

Upgrade axios to version 1.12.0 or higher.

References

medium severity

Use of a Broken or Risky Cryptographic Algorithm

  • Vulnerable module: jsonwebtoken
  • Introduced through: jsonwebtoken@8.5.1

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef jsonwebtoken@8.5.1
    Remediation: Upgrade to jsonwebtoken@9.0.0.

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

Improper Restriction of Security Token Assignment

  • Vulnerable module: jsonwebtoken
  • Introduced through: jsonwebtoken@8.5.1

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef jsonwebtoken@8.5.1
    Remediation: Upgrade to jsonwebtoken@9.0.0.

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

Improper Authentication

  • Vulnerable module: jsonwebtoken
  • Introduced through: jsonwebtoken@8.5.1

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef jsonwebtoken@8.5.1
    Remediation: Upgrade to jsonwebtoken@9.0.0.

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

Server-side Request Forgery (SSRF)

  • Vulnerable module: axios
  • Introduced through: axios@0.27.2

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef axios@0.27.2
    Remediation: Upgrade to axios@0.30.0.

Overview

axios is a promise-based HTTP client for the browser and Node.js.

Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF) due to the allowAbsoluteUrls attribute being ignored in the call to the buildFullPath function from the HTTP adapter. An attacker could launch SSRF attacks or exfiltrate sensitive data by tricking applications into sending requests to malicious endpoints.

PoC

const axios = require('axios');
const client = axios.create({baseURL: 'http://example.com/', allowAbsoluteUrls: false});
client.get('http://evil.com');

Remediation

Upgrade axios to version 0.30.0, 1.8.2 or higher.

References

medium severity

Server-side Request Forgery (SSRF)

  • Vulnerable module: axios
  • Introduced through: axios@0.27.2

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef axios@0.27.2
    Remediation: Upgrade to axios@0.30.0.

Overview

axios is a promise-based HTTP client for the browser and Node.js.

Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF) due to not setting allowAbsoluteUrls to false by default when processing a requested URL in buildFullPath(). It may not be obvious that this value is being used with the less safe default, and URLs that are expected to be blocked may be accepted. This is a bypass of the fix for the vulnerability described in CVE-2025-27152.

Remediation

Upgrade axios to version 0.30.0, 1.8.3 or higher.

References

medium severity

Missing Release of Resource after Effective Lifetime

  • Vulnerable module: inflight
  • Introduced through: glob@8.0.3, @jest/core@28.1.3 and others

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef glob@8.0.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 @jest/reporters@28.1.3 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-runtime@28.1.3 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 rimraf@3.0.2 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-runner@28.1.3 jest-runtime@28.1.3 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef bcrypt@5.1.1 @mapbox/node-pre-gyp@1.0.11 rimraf@3.0.2 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 jest-circus@28.1.3 jest-runtime@28.1.3 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 jest-runner@28.1.3 jest-runtime@28.1.3 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 @jest/reporters@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-runtime@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-runner@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 babel-jest@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 babel-jest@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-runtime@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-resolve-dependencies@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-runner@28.1.3 jest-runtime@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 jest-runner@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-runner@28.1.3 jest-runtime@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 jest-circus@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 jest-circus@28.1.3 jest-runtime@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 jest-runner@28.1.3 jest-runtime@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-runtime@28.1.3 @jest/globals@28.1.3 @jest/expect@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 jest-circus@28.1.3 @jest/expect@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 jest-circus@28.1.3 jest-runtime@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 jest-runner@28.1.3 jest-runtime@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-runner@28.1.3 jest-runtime@28.1.3 @jest/globals@28.1.3 @jest/expect@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 jest-circus@28.1.3 jest-runtime@28.1.3 @jest/globals@28.1.3 @jest/expect@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 glob@7.2.3 inflight@1.0.6
  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef @jest/core@28.1.3 jest-config@28.1.3 jest-runner@28.1.3 jest-runtime@28.1.3 @jest/globals@28.1.3 @jest/expect@28.1.3 jest-snapshot@28.1.3 @jest/transform@28.1.3 babel-plugin-istanbul@6.1.1 test-exclude@6.0.0 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

Prototype Pollution

  • Vulnerable module: minimist
  • Introduced through: swig@1.4.2

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef swig@1.4.2 optimist@0.6.1 minimist@0.0.10

Overview

minimist is a parse argument options module.

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

PoC by Snyk

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

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

Details

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

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

  • Unsafe Object recursive merge

  • Property definition by path

Unsafe Object recursive merge

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

merge (target, source)

  foreach property of source

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

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

    else

      target[property] = source[property]

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

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

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

Property definition by path

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

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

Types of attacks

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

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

Affected environments

The following environments are susceptible to a Prototype Pollution attack:

  • Application server

  • Web server

  • 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

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: axios
  • Introduced through: axios@0.27.2

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef axios@0.27.2
    Remediation: Upgrade to axios@0.29.0.

Overview

axios is a promise-based HTTP client for the browser and Node.js.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS). An attacker can deplete system resources by providing a manipulated string as input to the format method, causing the regular expression to exhibit a time complexity of O(n^2). This makes the server to become unable to provide normal service due to the excessive cost and time wasted in processing vulnerable regular expressions.

PoC

const axios = require('axios');

console.time('t1');
axios.defaults.baseURL = '/'.repeat(10000) + 'a/';
axios.get('/a').then(()=>{}).catch(()=>{});
console.timeEnd('t1');

console.time('t2');
axios.defaults.baseURL = '/'.repeat(100000) + 'a/';
axios.get('/a').then(()=>{}).catch(()=>{});
console.timeEnd('t2');


/* stdout
t1: 60.826ms
t2: 5.826s
*/

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 axios to version 0.29.0, 1.6.3 or higher.

References

medium severity

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: nodemailer
  • Introduced through: nodemailer@6.7.8

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef nodemailer@6.7.8
    Remediation: Upgrade to nodemailer@6.9.9.

Overview

nodemailer is an Easy as cake e-mail sending from your Node.js applications

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via the attachDataUrls parameter or when parsing attachments with an embedded file. An attacker can exploit this vulnerability by sending a specially crafted email that triggers inefficient regular expression evaluation, leading to excessive consumption of CPU resources.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  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 nodemailer to version 6.9.9 or higher.

References

medium severity

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: redis
  • Introduced through: acl@0.4.11

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef acl@0.4.11 redis@2.8.0

Overview

redis is an A high performance Redis client.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS). When a client is in monitoring mode, monitor_regex, which is used to detected monitor messages` could cause exponential backtracking on some strings, leading to denial of service.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

  • A The string must start with the letter 'A'
  • (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
  • D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

  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 redis to version 3.1.1 or higher.

References

medium severity

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: uglify-js
  • Introduced through: swig@1.4.2

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef swig@1.4.2 uglify-js@2.4.24

Overview

uglify-js is a JavaScript parser, minifier, compressor and beautifier toolkit.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via the string_template and the decode_template functions.

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 uglify-js to version 3.14.3 or higher.

References

medium severity
patched

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: uglify-js
  • Introduced through: swig@1.4.2

Vulnerability patched for: swig uglify-js

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef swig@1.4.2 uglify-js@2.4.24
    Remediation: Open PR to patch uglify-js@2.4.24.

medium severity

Regular Expression Denial of Service (ReDoS)

  • Vulnerable module: zxcvbn
  • Introduced through: zxcvbn@4.4.2

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef zxcvbn@4.4.2

Overview

zxcvbn is a realistic password strength estimation

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via the repeat_match functionality, due to the usage of an insecure regex in lazy_anchored variable.

PoC

const zxcvbn = require("zxcvbn");
attackStr = '\x00\x00' + ('\x00'.repeat(54773)) + '\n'
zxcvbn(attackStr)

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

There is no fixed version for zxcvbn.

References

low severity

Prototype Pollution

  • Vulnerable module: minimist
  • Introduced through: swig@1.4.2

Detailed paths

  • Introduced through: @weareopensource/node@weareopensource/typescript#c7b3ed27748b0c58a93563e19518e5cc808b9eef swig@1.4.2 optimist@0.6.1 minimist@0.0.10

Overview

minimist is a parse argument options module.

Affected versions of this package are vulnerable to Prototype Pollution 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