{"id":"UBUNTU-CVE-2018-1000027","details":"The Squid Software Foundation Squid HTTP Caching Proxy version prior to version 4.0.23 contains a NULL Pointer Dereference vulnerability in HTTP Response X-Forwarded-For header processing that can result in Denial of Service to all clients of the proxy. This attack appear to be exploitable via Remote HTTP server responding with an X-Forwarded-For header to certain types of HTTP request. This vulnerability appears to have been fixed in 4.0.23 and later.","modified":"2026-02-04T04:19:52.511568Z","published":"2018-01-29T00:00:00Z","related":["USN-3557-1","USN-4059-2"],"upstream":["CVE-2018-1000027"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2018-1000027"},{"type":"REPORT","url":"http://www.squid-cache.org/Advisories/SQUID-2018_2.txt"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-3557-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4059-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2018-1000027"}],"affected":[{"package":{"name":"squid3","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/squid3@3.3.8-1ubuntu6.11?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.3.8-1ubuntu6.11"}]}],"versions":["3.3.8-1ubuntu3","3.3.8-1ubuntu4","3.3.8-1ubuntu5","3.3.8-1ubuntu6","3.3.8-1ubuntu6.1","3.3.8-1ubuntu6.2","3.3.8-1ubuntu6.3","3.3.8-1ubuntu6.4","3.3.8-1ubuntu6.6","3.3.8-1ubuntu6.8","3.3.8-1ubuntu6.9","3.3.8-1ubuntu6.10"],"ecosystem_specific":{"binaries":[{"binary_name":"squid","binary_version":"3.3.8-1ubuntu6.11"},{"binary_name":"squid-cgi","binary_version":"3.3.8-1ubuntu6.11"},{"binary_name":"squid-purge","binary_version":"3.3.8-1ubuntu6.11"},{"binary_name":"squid3","binary_version":"3.3.8-1ubuntu6.11"},{"binary_name":"squid3-common","binary_version":"3.3.8-1ubuntu6.11"},{"binary_name":"squidclient","binary_version":"3.3.8-1ubuntu6.11"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-1000027.json"}},{"package":{"name":"squid3","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/squid3@3.5.12-1ubuntu7.5?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.5.12-1ubuntu7.5"}]}],"versions":["3.3.8-1ubuntu16","3.3.8-1ubuntu17","3.5.12-1ubuntu6","3.5.12-1ubuntu7","3.5.12-1ubuntu7.1","3.5.12-1ubuntu7.2","3.5.12-1ubuntu7.3","3.5.12-1ubuntu7.4"],"ecosystem_specific":{"binaries":[{"binary_name":"squid","binary_version":"3.5.12-1ubuntu7.5"},{"binary_name":"squid-cgi","binary_version":"3.5.12-1ubuntu7.5"},{"binary_name":"squid-common","binary_version":"3.5.12-1ubuntu7.5"},{"binary_name":"squid-purge","binary_version":"3.5.12-1ubuntu7.5"},{"binary_name":"squid3","binary_version":"3.5.12-1ubuntu7.5"},{"binary_name":"squidclient","binary_version":"3.5.12-1ubuntu7.5"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-1000027.json"}},{"package":{"name":"squid3","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/squid3@3.5.23-5ubuntu2?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.5.23-5ubuntu2"}]}],"versions":["3.5.23-5ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"squid","binary_version":"3.5.23-5ubuntu2"},{"binary_name":"squid-cgi","binary_version":"3.5.23-5ubuntu2"},{"binary_name":"squid-common","binary_version":"3.5.23-5ubuntu2"},{"binary_name":"squid-purge","binary_version":"3.5.23-5ubuntu2"},{"binary_name":"squid3","binary_version":"3.5.23-5ubuntu2"},{"binary_name":"squidclient","binary_version":"3.5.23-5ubuntu2"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-1000027.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"low"}]}