CVE-2009-2621

5.0 MEDIUM 23% exploit odds Fix listed Memory safety

What it is

Squid 3.0 through 3.0.STABLE16 and 3.1 through 3.1.0.11 does not properly enforce "buffer limits and related bound checks," which allows remote attackers to cause a denial of service via (1) an incomplete request or (2) a request with a large header size, related to (a) HttpMsg.cc and (b) client_side.cc.

At a glance

Exploitability: Can be exploited over the network without logging in. Limited direct impact.
Exploit odds: 23.0% chance of exploitation in the next 30 days (EPSS). Higher than most.
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2009-07-28 17:30 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-16 23:09 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 23.0% in the next 30 days (EPSS).
Severity: 5.0 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2009-07-28 17:30 UTC
Last modified: 2026-06-16 23:09 UTC
Exploit probability: 23.0% · EPSS, next 30 days
Weakness: CWE-119 · Buffer errors
Record status: Modified

Affected

squid-cache Squid 3.0
squid-cache Squid 3.1
squid-cache Squid 3.1.0.1
squid-cache Squid 3.1.0.2
squid-cache Squid 3.1.0.3
squid-cache Squid 3.1.0.4

Attack profile CVSS 2.0 · 5.0

Attack vector: Network
Complexity: Low
Authentication: None
Confidentiality: None
Integrity: None
Availability: Partial

Raw vector

AV:N/AC:L/Au:N/C:N/I:N/A:P

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2009-2621.md and follow it. Check whether this project is affected by CVE-2009-2621. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record