{"id":"CVE-2020-7663","details":"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.","aliases":["GHSA-g6wq-qcwm-j5g2"],"modified":"2026-04-02T06:16:44.031017Z","published":"2020-06-02T19:15:12.467Z","related":["GHSA-g6wq-qcwm-j5g2","SNYK-RUBY-WEBSOCKETEXTENSIONS-570830","SUSE-SU-2023:0127-1","openSUSE-SU-2024:11357-1","openSUSE-SU-2024:13173-1","openSUSE-SU-2024:14180-1","openSUSE-SU-2025:15130-1","openSUSE-SU-2026:10368-1"],"references":[{"type":"ADVISORY","url":"https://blog.jcoglan.com/2020/06/02/redos-vulnerability-in-websocket-extensions"},{"type":"ADVISORY","url":"https://github.com/faye/websocket-extensions-ruby/security/advisories/GHSA-g6wq-qcwm-j5g2"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2020/08/msg00031.html"},{"type":"ADVISORY","url":"https://usn.ubuntu.com/4502-1/"},{"type":"FIX","url":"https://github.com/faye/websocket-extensions-ruby/commit/aa156a439da681361ed6f53f1a8131892418838b"},{"type":"EVIDENCE","url":"https://snyk.io/vuln/SNYK-RUBY-WEBSOCKETEXTENSIONS-570830"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/faye/websocket-extensions-ruby","events":[{"introduced":"0"},{"fixed":"aa156a439da681361ed6f53f1a8131892418838b"}]},{"type":"GIT","repo":"https://github.com/faye/websocket-extensions-ruby","events":[{"introduced":"0"},{"fixed":"aa156a439da681361ed6f53f1a8131892418838b"}]}],"versions":["0.1.0","0.1.1","0.1.2","0.1.3","0.1.4"],"database_specific":{"unresolved_ranges":[{"events":[{"introduced":"0"},{"fixed":"0.1.5"}]},{"events":[{"introduced":"0"},{"last_affected":"9.0"}]},{"events":[{"introduced":"0"},{"last_affected":"16.04"}]},{"events":[{"introduced":"0"},{"last_affected":"18.04"}]},{"events":[{"introduced":"0"},{"last_affected":"20.04"}]}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-7663.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}