CVE-2021-33620
MEDIUM
6.5
CVSS Score
Published: May 28, 2021 at 12:00 AM UTC
Updated: June 17, 2026 at 03:54 AM UTC
3 products affected across 3 vendorsDebian LinuxFedoraCache Squid
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Severity
MEDIUM6.5
Exploit prediction
EPSS 80%
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.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Debian Linux· Debiandrupal
95%v < 4.155.0 ≤ v < 5.0.6
Affected range stops below 4.15, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.0.6, so it looks safe — our inference, not a vendor statement
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
- http://www.squid-cache.org/Versions/v4/changesets/squid-4-1e05a85bd28c22c9ca5d3ac9f5e86d6269ec0a8c.patch
- http://www.squid-cache.org/Versions/v5/changesets/squid-5-8af775ed98bfd610f9ce762fe177e01b2675588c.patch
- https://github.com/squid-cache/squid/security/advisories/GHSA-572g-rvwr-6c7f
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQ3U54ZCNXR44QRPW3AV2VCS6K3TKCF/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T4EPIWUZDJAXADDHVOPKRBTQHPBR6H66/
References (8)
Mailing ListThird Party Advisory
Source: [email protected]
http://seclists.org/fulldisclosure/2023/Oct/14Mailing ListThird Party Advisory
Source: [email protected]
http://www.openwall.com/lists/oss-security/2023/10/11/3Mailing ListPatchVendor Advisory
Source: [email protected]
http://www.squid-cache.org/Versions/v4/changesets/squid-4-1e05a85bd28c22c9ca5d3ac9f5e86d6269ec0a8c.patchMailing ListPatchVendor Advisory
Source: [email protected]
http://www.squid-cache.org/Versions/v5/changesets/squid-5-8af775ed98bfd610f9ce762fe177e01b2675588c.patchPatchThird Party Advisory
Source: [email protected]
https://github.com/squid-cache/squid/security/advisories/GHSA-572g-rvwr-6c7fMailing ListThird Party Advisory
Source: [email protected]
https://lists.debian.org/debian-lts-announce/2021/06/msg00014.htmlCVSS
6.5MEDIUMmitre
- Attack Vector
- NETWORK
- Complexity
- LOW
- Privileges
- LOW
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- NONE
- Integrity
- NONE
- Availability
- HIGH
Vector?
Quick Info
StatusMODIFIED
CWE
CWE-20
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