Vulnerability in Websocket-Extensions Project
CVE-2020-7663
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.045 (91.2th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 91st percentile — 91.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.045 · newest: 0.045 · change: 0.000
Affected products
- Websocket-Extensions Project
- Canonical Ubuntu Linux — versions 16.04, 18.04, 20.04
- Debian Linux — versions 9.0
- Websocket-Extensions (Ruby) — versions All versions prior to 0.1.5
Public proof-of-concept exploits
References
- github.com/faye/websocket-extensions-ruby/security/advisories/GHSA-g6wq-qcwm-j5… (Third Party Advisory)
- github.com/faye/websocket-extensions-ruby/commit/aa156a439da681361ed6f53f1a8131… (Patch, Third Party Advisory)
- blog.jcoglan.com/2020/06/02/redos-vulnerability-in-websocket-extensions (Third Party Advisory)
- snyk.io/vuln/SNYK-RUBY-WEBSOCKETEXTENSIONS-570830 (Exploit, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2020/08/msg00031.html (mailing-list, Mailing List, Third Party Advisory)
- usn.ubuntu.com/4502-1/ (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-7663?
- CVE-2020-7663 is a high-severity vulnerability in Websocket-Extensions Project. CVSS score: 7.5/10. Published 2020-06-02.
- How severe is CVE-2020-7663?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2020-7663 known to be exploited?
- 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.