CVE-2021-33620

Description

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.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 8.41% Top 10%
Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory squid-cache.org Vendor Advisory squid-cache.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://github.com/squid-cache/squid/security/advisories/GHSA-572g-rvwr-6c7f third party advisory patch
http://www.squid-cache.org/Versions/v5/changesets/squid-5-8af775ed98bfd610f9ce762fe177e01b2675588c.patch mailing list patch vendor advisory
http://www.squid-cache.org/Versions/v4/changesets/squid-4-1e05a85bd28c22c9ca5d3ac9f5e86d6269ec0a8c.patch mailing list patch vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQ3U54ZCNXR44QRPW3AV2VCS6K3TKCF/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T4EPIWUZDJAXADDHVOPKRBTQHPBR6H66/ vendor advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00014.html third party advisory mailing list
http://www.openwall.com/lists/oss-security/2023/10/11/3 third party advisory mailing list
http://seclists.org/fulldisclosure/2023/Oct/14 third party advisory mailing list

Frequently Asked Questions

What is the severity of CVE-2021-33620?
CVE-2021-33620 has been scored as a medium severity vulnerability.
How to fix CVE-2021-33620?
To fix CVE-2021-33620, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-33620 being actively exploited in the wild?
It is possible that CVE-2021-33620 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~8% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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