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 bypass intended restrictions and gain access to a backend proxy via a CONNECT request.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 20.8%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.
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.
- CVSS 2.0
- 6.8 MEDIUMAV:N/AC:M/Au:N/C:P/I:P/A:P
- EPSS
- 20.84% probability · 98th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-264
- Affected
- fedoraproject/fedora · debian/debian linux · squid-cache/squid
- Source
- cve@mitre.org
EPSS 20.8% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
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/2015/07/17/14Exploit
- http://www.securityfocus.com/bid/75553
- http://www.securitytracker.com/id/1032873
- http://www.squid-cache.org/Advisories/SQUID-2015_2.txtVendor Advisory
- http://www.squid-cache.org/Versions/v3/3.1/changesets/squid-3.1-10494.patchExploit, Vendor Advisory
- http://www.squid-cache.org/Versions/v3/3.4/changesets/squid-3.4-13225.patchExploit, Vendor Advisory
- http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-13856.patchExploit, Vendor Advisory
- 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/2015/07/17/14Exploit
- http://www.securityfocus.com/bid/75553
- http://www.securitytracker.com/id/1032873
- http://www.squid-cache.org/Advisories/SQUID-2015_2.txtVendor Advisory
- http://www.squid-cache.org/Versions/v3/3.1/changesets/squid-3.1-10494.patchExploit, Vendor Advisory
- http://www.squid-cache.org/Versions/v3/3.4/changesets/squid-3.4-13225.patchExploit, Vendor Advisory
- http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-13856.patchExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.