CVE-2015-5400 Security feature bypass in n/a

What is CVE-2015-5400?

CVE-2015-5400 is a medium-severity vulnerability in Debian Debian Linux, published on 28 Sep 2015. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-264

Which versions are affected by CVE-2015-5400?

It affects 3 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Squid-Cache Squid.

How do I fix CVE-2015-5400?

Upgrade to a fixed version.

Is CVE-2015-5400 being exploited?

There is no known exploitation of CVE-2015-5400 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2015-5400, DLA-286-1, DSA-3327-1, GHSA-9pj4-fqm8-w5x7, MGASA-2015-0347, UBUNTU-CVE-2015-5400.