{"id":"CVE-2015-5400","url":"https://www.cyber-defence.io/tools/cve/CVE-2015-5400","generatedAt":"2026-10-27T19:52:46.914Z","title":"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.","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.","published":"2015-09-28T20:59:03.000Z","lastModified":"2026-06-17T00:29:04.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"2.0","score":6.8,"severity":"MEDIUM","vector":"AV:N/AC:M/Au:N/C:P/I:P/A:P"},"cwe":["CWE-264"],"affected":["fedoraproject/fedora","debian/debian linux","squid-cache/squid"],"epss":{"score":0.20844,"percentile":0.9753,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"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."},"changes":[],"references":[{"url":"http://lists.fedoraproject.org/pipermail/package-announce/2016-May/183598.html","source":"cve@mitre.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html","source":"cve@mitre.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html","source":"cve@mitre.org"},{"url":"http://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html","source":"cve@mitre.org"},{"url":"http://www.debian.org/security/2015/dsa-3327","source":"cve@mitre.org"},{"url":"http://www.openwall.com/lists/oss-security/2015/07/06/8","source":"cve@mitre.org"},{"url":"http://www.openwall.com/lists/oss-security/2015/07/09/12","source":"cve@mitre.org"},{"url":"http://www.openwall.com/lists/oss-security/2015/07/10/2","source":"cve@mitre.org"},{"url":"http://www.openwall.com/lists/oss-security/2015/07/17/14","tags":["Exploit"],"source":"cve@mitre.org"},{"url":"http://www.securityfocus.com/bid/75553","source":"cve@mitre.org"},{"url":"http://www.securitytracker.com/id/1032873","source":"cve@mitre.org"},{"url":"http://www.squid-cache.org/Advisories/SQUID-2015_2.txt","tags":["Vendor Advisory"],"source":"cve@mitre.org"},{"url":"http://www.squid-cache.org/Versions/v3/3.1/changesets/squid-3.1-10494.patch","tags":["Exploit","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"http://www.squid-cache.org/Versions/v3/3.4/changesets/squid-3.4-13225.patch","tags":["Exploit","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-13856.patch","tags":["Exploit","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"http://lists.fedoraproject.org/pipermail/package-announce/2016-May/183598.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.debian.org/security/2015/dsa-3327","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.openwall.com/lists/oss-security/2015/07/06/8","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.openwall.com/lists/oss-security/2015/07/09/12","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.openwall.com/lists/oss-security/2015/07/10/2","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.openwall.com/lists/oss-security/2015/07/17/14","tags":["Exploit"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securityfocus.com/bid/75553","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securitytracker.com/id/1032873","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.squid-cache.org/Advisories/SQUID-2015_2.txt","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.squid-cache.org/Versions/v3/3.1/changesets/squid-3.1-10494.patch","tags":["Exploit","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.squid-cache.org/Versions/v3/3.4/changesets/squid-3.4-13225.patch","tags":["Exploit","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-13856.patch","tags":["Exploit","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2015-5400","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}