Description
ws is an open source WebSocket client and server library for Node.js. A specially crafted value of the `Sec-Websocket-Protocol` header can be used to significantly slow down a ws server. The vulnerability has been fixed in [email protected] (https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff). 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.
References (4)
Core 4
Core References
Exploit, Mitigation, Patch, Third Party Advisory x_refsource_confirm
https://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693
Patch, Third Party Advisory x_refsource_misc
https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff
Mailing List mailing-list
x_refsource_mlist
https://lists.apache.org/thread.html/rdfa7b6253c4d6271e31566ecd5f30b7ce1b8fb2c89d52b8c4e0f4e30%40%3Ccommits.tinkerpop.apache.org%3E
Third Party Advisory x_refsource_confirm
https://security.netapp.com/advisory/ntap-20210706-0005/
Scores
CVSS v3
5.3
EPSS
0.0045
EPSS Percentile
63.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Details
CWE
CWE-400
Status
published
Products (3)
netapp/e-series_performance_analyzer
npm/ws
7.0.0 - 7.4.6npm
ws_project/ws
5.0.0 - 6.2.2
Published
May 25, 2021
Tracked Since
Feb 18, 2026