High · published June 17, 2024
ws is an open source WebSocket client and server for Node.js. A request with a number of headers exceeding theserver.maxHeadersCount threshold could be used to crash a ws server. The vulnerability was fixed in [email protected] (e55e510) and backported to [email protected] (22c2876), [email protected] (eeb76d3), and [email protected] (4abd8f6). 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.