CVE-2021-32640

Public Exploit
ReDoS in Sec-Websocket-Protocol header

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 ws@7.4.6 (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.

Category

5.3
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.49%
Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory netapp.com
Affected: websockets ws
Published at:
Updated at:

References

Link Tags
https://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693 patch exploit mitigation third party advisory
https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff third party advisory patch
https://lists.apache.org/thread.html/rdfa7b6253c4d6271e31566ecd5f30b7ce1b8fb2c89d52b8c4e0f4e30%40%3Ccommits.tinkerpop.apache.org%3E mailing list
https://security.netapp.com/advisory/ntap-20210706-0005/ third party advisory

Frequently Asked Questions

What is the severity of CVE-2021-32640?
CVE-2021-32640 has been scored as a medium severity vulnerability.
How to fix CVE-2021-32640?
To fix CVE-2021-32640, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-32640 being actively exploited in the wild?
It is possible that CVE-2021-32640 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-32640?
CVE-2021-32640 affects websockets ws.
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