CVE-2024-23638
Due to an expired pointer reference bug, Squid prior to version 6.6 is vulnerable to a Denial of Service attack against Cache Manager error responses.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 60.1%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
Description
Squid is a caching proxy for the Web. Due to an expired pointer reference bug, Squid prior to version 6.6 is vulnerable to a Denial of Service attack against Cache Manager error responses. This problem allows a trusted client to perform Denial of Service when generating error pages for Client Manager reports. Squid older than 5.0.5 have not been tested and should be assumed to be vulnerable. All Squid-5.x up to and including 5.9 are vulnerable. All Squid-6.x up to and including 6.5 are vulnerable. This bug is fixed by Squid version 6.6. In addition, patches addressing this problem for the stable releases can be found in Squid's patch archives. As a workaround, prevent access to Cache Manager using Squid's main access control: `http_access deny manager`.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 60.05% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-825, CWE-672
- Affected
- squid-cache/squid
- Source
- security-advisories@github.com
EPSS 60.1% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.squid-cache.org/Versions/v5/SQUID-2023_11.patchMailing List, Patch
- http://www.squid-cache.org/Versions/v6/SQUID-2023_11.patchMailing List, Patch
- https://github.com/squid-cache/squid/commit/290ae202883ac28a48867079c2fb34c40efd382bPatch
- https://github.com/squid-cache/squid/commit/e8118a7381213f5cfcdeb4cec1d2d854bfd261c8Patch
- https://github.com/squid-cache/squid/security/advisories/GHSA-j49p-553x-48rxVendor Advisory
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/7R4KPSO3MQT3KAOZV7LC2GG3CYMCGK7H/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XWQHRDRHDM5PQTU6BHH4C5KGL37X6TVI/
- https://megamansec.github.io/Squid-Security-Audit/stream-assert.htmlExploit
- https://security.netapp.com/advisory/ntap-20240208-0010/
- http://www.squid-cache.org/Versions/v5/SQUID-2023_11.patchMailing List, Patch
- http://www.squid-cache.org/Versions/v6/SQUID-2023_11.patchMailing List, Patch
- https://github.com/squid-cache/squid/commit/290ae202883ac28a48867079c2fb34c40efd382bPatch
- https://github.com/squid-cache/squid/commit/e8118a7381213f5cfcdeb4cec1d2d854bfd261c8Patch
- https://github.com/squid-cache/squid/security/advisories/GHSA-j49p-553x-48rxVendor Advisory
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/7R4KPSO3MQT3KAOZV7LC2GG3CYMCGK7H/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XWQHRDRHDM5PQTU6BHH4C5KGL37X6TVI/
- https://megamansec.github.io/Squid-Security-Audit/stream-assert.htmlExploit
- https://security.netapp.com/advisory/ntap-20240208-0010/
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.