CVE-2015-5400

Severity: medium (CVSS 6.8 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 20.8% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2015-09-28 · updated 2026-06-17
Weakness: CWE-264

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.

Affected products

Debian Linux: 7.0, 8.0
Fedoraproject Fedora: 22
Squid: through 3.5.2

References

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

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