Improper input validation in Squid-Cache Squid
CVE-2021-33620
Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.796 (99.6th percentile), scored .
High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.796 · newest: 0.796 · change: 0.000
Affected products
- Squid-Cache Squid
- Debian Linux — versions 9.0
- Fedoraproject Fedora — versions 33, 34
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/squid-cache/squid/security/advisories/GHSA-572g-rvwr-6c7f (Patch, Third Party Advisory)
- www.squid-cache.org/Versions/v5/changesets/squid-5-8af775ed98bfd610f9ce762fe177… (Patch, Mailing List, Vendor Advisory)
- www.squid-cache.org/Versions/v4/changesets/squid-4-1e05a85bd28c22c9ca5d3ac9f5e8… (Patch, Mailing List, Vendor Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.debian.org/debian-lts-announce/2021/06/msg00014.html (mailing-list, Mailing List, Third Party Advisory)
- www.openwall.com/lists/oss-security/2023/10/11/3 (mailing-list, Mailing List, Third Party Advisory)
- seclists.org/fulldisclosure/2023/Oct/14 (mailing-list, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-33620?
- CVE-2021-33620 is a medium-severity vulnerability in Squid-Cache Squid, classified under Improper Input Validation. CVSS score: 6.5/10. Published 2021-05-28.
- How severe is CVE-2021-33620?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2021-33620 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.