CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2020-7663
High (7.5). EPSS 4.6% chance of exploitation in the next 30 days. Fixed in websocket-extensions 0.1.5.
websocket-extensions ruby module prior to 0.1.5 allows Denial of Service (DoS) via Regex Backtracking. The extension parser may take quadratic time when parsing a header containing an unclosed string parameter value whose content is a repeating two-byte sequence of a backslash and some other character. This could be abused by an attacker to conduct Regex Denial Of Service (ReDoS) on a single-threaded server by providing a malicious payload with the Sec-WebSocket-Extensions header.
Severity
- EPSS
- 4.6% chance of exploitation in the next 30 days; higher than 91% of CVEs (scores of 2026-10-31)
- Published
- Modified
- Record from
- the NVD, synced
Affected
- canonical:ubuntu_linux
- debian:debian_linux
- websocket-extensions_project:websocket-extensions
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-g6wq-qcwm-j5g2 | RubyGems | websocket-extensions | <0.1.5 | 0.1.5 |
References
- https://blog.jcoglan.com/2020/06/02/redos-vulnerability-in-websocket-extensions
- https://github.com/faye/websocket-extensions-ruby/commit/aa156a439da681361ed6f53f1a8131892418838b
- https://github.com/faye/websocket-extensions-ruby/security/advisories/GHSA-g6wq-qcwm-j5g2
- https://lists.debian.org/debian-lts-announce/2020/08/msg00031.html
- https://snyk.io/vuln/SNYK-RUBY-WEBSOCKETEXTENSIONS-570830