{"id":"UBUNTU-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.","modified":"2026-02-04T03:15:20.991474Z","published":"2020-06-02T19:15:00Z","related":["USN-4502-1"],"upstream":["CVE-2020-7663"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-7663"},{"type":"REPORT","url":"https://blog.jcoglan.com/2020/06/02/redos-vulnerability-in-websocket-extensions"},{"type":"REPORT","url":"https://github.com/faye/websocket-extensions-ruby/commit/aa156a439da681361ed6f53f1a8131892418838b"},{"type":"REPORT","url":"https://github.com/faye/websocket-extensions-ruby/security/advisories/GHSA-g6wq-qcwm-j5g2"},{"type":"REPORT","url":"https://snyk.io/vuln/SNYK-RUBY-WEBSOCKETEXTENSIONS-570830"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4502-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2020-7663"}],"affected":[{"package":{"name":"ruby-websocket-extensions","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/ruby-websocket-extensions@0.1.2-1+deb9u1build0.16.04.1?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.1.2-1+deb9u1build0.16.04.1"}]}],"versions":["0.1.2-1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.1.2-1+deb9u1build0.16.04.1","binary_name":"ruby-websocket-extensions"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-7663.json"}},{"package":{"name":"ruby-websocket-extensions","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/ruby-websocket-extensions@0.1.2-1+deb9u1build0.18.04.1?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.1.2-1+deb9u1build0.18.04.1"}]}],"versions":["0.1.2-1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.1.2-1+deb9u1build0.18.04.1","binary_name":"ruby-websocket-extensions"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-7663.json"}},{"package":{"name":"ruby-websocket-extensions","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/ruby-websocket-extensions@0.1.2-1+deb9u1build0.20.04.1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.1.2-1+deb9u1build0.20.04.1"}]}],"versions":["0.1.2-1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.1.2-1+deb9u1build0.20.04.1","binary_name":"ruby-websocket-extensions"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-7663.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}