Medium severity · published May 28, 2021
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
6.5
CVSS
79.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)79.6% · higher than 100% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DL
Debian Linux · Debian
9.0 · source: NVD
FE
Fedora · Fedoraproject
33; 34 · source: NVD
SQ
Squid · Squid-cache
before 4.15; 5.0 before 5.0.6 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-33620
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-33620
Mailing List
http://seclists.org/fulldisclosure/2023/Oct/14
Mailing List
http://www.openwall.com/lists/oss-security/2023/10/11/3
Mailing List
http://www.squid-cache.org/Versions/v4/changesets/squid-4-1e05a85bd28c22c9ca5d3ac9f5e86d6269ec0a8c.patch
Mailing List
http://www.squid-cache.org/Versions/v5/changesets/squid-5-8af775ed98bfd610f9ce762fe177e01b2675588c.patch
Patch
https://github.com/squid-cache/squid/security/advisories/GHSA-572g-rvwr-6c7f
Mailing List
https://lists.debian.org/debian-lts-announce/2021/06/msg00014.html
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