CVE-2024-37894 — Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to an Out-of-bounds Write error when assigning ESI variables, Squid is susceptible to a Memory Corruption error. This error can lead to a Denial of Service attack.

01What is this vulnerability?

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to an Out-of-bounds Write error when assigning ESI variables, Squid is susceptible to a Memory Corruption error. This error can lead to a Denial of Service attack.

02Affected products

Vendor	Product	Versions
squid-cache	squid	>= 3.0, <= 3.5.28, >= 4.0, <= 4.16, >= 5.0, <= 5.9, >= 6.0, <= 6.9

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2024-06-25T19:39:02.376Z
• Last modified: 2025-11-03T20:38:02.746Z

09References

• github.com — https://github.com/squid-cache/squid/security/advisories/GHSA-wgvf-q977-9xjg
• github.com — https://github.com/squid-cache/squid/commit/f411fe7d75197852f0e5ee85027a06d58dd8…
• security.netapp.com — https://security.netapp.com/advisory/ntap-20240719-0001/