Squid Web Proxy up to 3.5.28/4.16/5.9/6.9 ESI Variable out-of-bounds write

Summaryinfo

A vulnerability, which was classified as critical, has been found in Squid Web Proxy up to 3.5.28/4.16/5.9/6.9. This issue affects some unknown processing of the component ESI Variable Handler. The manipulation leads to out-of-bounds write. This vulnerability is traded as CVE-2024-37894. It is possible to initiate the attack remotely. There is no exploit available. Applying a patch is the recommended action to fix this issue.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Squid Web Proxy up to 3.5.28/4.16/5.9/6.9. This issue affects an unknown functionality of the component ESI Variable Handler. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is availability. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2024-37894 since 06/10/2024. The exploitation is known to be difficult. The attack may be initiated remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/15/2025).

The vulnerability scanner Nessus provides a plugin with the ID 232586 (Debian dla-4083 : squid - security update), which helps to determine the existence of the flaw in a target environment.

Applying the patch f411fe7d75197852f0e5ee85027a06d58dd8df4c is able to eliminate this problem. The bugfix is ready for download at github.com.

The vulnerability is also documented in the databases at Tenable (232586) and CERT Bund (WID-SEC-2025-1850). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Xerox FreeFlow Print Server

Productinfo

Type

• Firewall Software

Vendor

• Squid

Name

• Web Proxy

Version

• 3.5.0
• 3.5.1
• 3.5.2
• 3.5.3
• 3.5.4
• 3.5.5
• 3.5.6
• 3.5.7
• 3.5.8
• 3.5.9
• 3.5.10
• 3.5.11
• 3.5.12
• 3.5.13
• 3.5.14
• 3.5.15
• 3.5.16
• 3.5.17
• 3.5.18
• 3.5.19
• 3.5.20
• 3.5.21
• 3.5.22
• 3.5.23
• 3.5.24
• 3.5.25
• 3.5.26
• 3.5.27
• 3.5.28
• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 5.0
• 5.1
• 5.2
• 5.3
• 5.4
• 5.5
• 5.6
• 5.7
• 5.8
• 5.9
• 6.0
• 6.1
• 6.2
• 6.3
• 6.4
• 6.5
• 6.6
• 6.7
• 6.8
• 6.9

License

• open-source

Website

• Vendor: http://www.squid-cache.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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