{"id":"UBUNTU-CVE-2019-12522","details":"An issue was discovered in Squid through 4.7. When Squid is run as root, it spawns its child processes as a lesser user, by default the user nobody. This is done via the leave_suid call. leave_suid leaves the Saved UID as 0. This makes it trivial for an attacker who has compromised the child process to escalate their privileges back to root.","modified":"2026-04-13T10:50:26.388213Z","published":"2020-04-15T19:15:00Z","upstream":["CVE-2019-12522"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2019-12522"},{"type":"REPORT","url":"https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12522.txt"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2019-12522"}],"affected":[{"package":{"name":"squid3","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/squid3@3.5.12-1ubuntu7.16+esm6?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"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","3.5.12-1ubuntu7.5","3.5.12-1ubuntu7.6","3.5.12-1ubuntu7.7","3.5.12-1ubuntu7.8","3.5.12-1ubuntu7.9","3.5.12-1ubuntu7.10","3.5.12-1ubuntu7.11","3.5.12-1ubuntu7.12","3.5.12-1ubuntu7.13","3.5.12-1ubuntu7.14","3.5.12-1ubuntu7.15","3.5.12-1ubuntu7.16","3.5.12-1ubuntu7.16+esm1","3.5.12-1ubuntu7.16+esm2","3.5.12-1ubuntu7.16+esm3","3.5.12-1ubuntu7.16+esm4","3.5.12-1ubuntu7.16+esm5","3.5.12-1ubuntu7.16+esm6"],"ecosystem_specific":{"binaries":[{"binary_version":"3.5.12-1ubuntu7.16+esm6","binary_name":"squid"},{"binary_version":"3.5.12-1ubuntu7.16+esm6","binary_name":"squid-cgi"},{"binary_version":"3.5.12-1ubuntu7.16+esm6","binary_name":"squid-common"},{"binary_version":"3.5.12-1ubuntu7.16+esm6","binary_name":"squid-purge"},{"binary_version":"3.5.12-1ubuntu7.16+esm6","binary_name":"squid3"},{"binary_version":"3.5.12-1ubuntu7.16+esm6","binary_name":"squidclient"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2019/UBUNTU-CVE-2019-12522.json"}},{"package":{"name":"squid3","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/squid3@3.5.27-1ubuntu1.14+esm5?arch=source&distro=esm-infra/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.5.23-5ubuntu1","3.5.23-5ubuntu2","3.5.27-1ubuntu1","3.5.27-1ubuntu1.1","3.5.27-1ubuntu1.2","3.5.27-1ubuntu1.3","3.5.27-1ubuntu1.4","3.5.27-1ubuntu1.5","3.5.27-1ubuntu1.6","3.5.27-1ubuntu1.7","3.5.27-1ubuntu1.8","3.5.27-1ubuntu1.9","3.5.27-1ubuntu1.10","3.5.27-1ubuntu1.11","3.5.27-1ubuntu1.12","3.5.27-1ubuntu1.13","3.5.27-1ubuntu1.14","3.5.27-1ubuntu1.14+esm1","3.5.27-1ubuntu1.14+esm2","3.5.27-1ubuntu1.14+esm3","3.5.27-1ubuntu1.14+esm4","3.5.27-1ubuntu1.14+esm5"],"ecosystem_specific":{"binaries":[{"binary_version":"3.5.27-1ubuntu1.14+esm5","binary_name":"squid"},{"binary_version":"3.5.27-1ubuntu1.14+esm5","binary_name":"squid-cgi"},{"binary_version":"3.5.27-1ubuntu1.14+esm5","binary_name":"squid-common"},{"binary_version":"3.5.27-1ubuntu1.14+esm5","binary_name":"squid-purge"},{"binary_version":"3.5.27-1ubuntu1.14+esm5","binary_name":"squid3"},{"binary_version":"3.5.27-1ubuntu1.14+esm5","binary_name":"squidclient"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2019/UBUNTU-CVE-2019-12522.json"}},{"package":{"name":"squid","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/squid@4.10-1ubuntu1.13+esm2?arch=source&distro=esm-infra/focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.8-1ubuntu2","4.8-1ubuntu3","4.9-2ubuntu1","4.9-2ubuntu2","4.9-2ubuntu3","4.9-2ubuntu4","4.10-1ubuntu1","4.10-1ubuntu1.1","4.10-1ubuntu1.2","4.10-1ubuntu1.3","4.10-1ubuntu1.4","4.10-1ubuntu1.5","4.10-1ubuntu1.6","4.10-1ubuntu1.7","4.10-1ubuntu1.8","4.10-1ubuntu1.9","4.10-1ubuntu1.10","4.10-1ubuntu1.11","4.10-1ubuntu1.12","4.10-1ubuntu1.13","4.10-1ubuntu1.13+esm1","4.10-1ubuntu1.13+esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"4.10-1ubuntu1.13+esm2","binary_name":"squid"},{"binary_version":"4.10-1ubuntu1.13+esm2","binary_name":"squid-cgi"},{"binary_version":"4.10-1ubuntu1.13+esm2","binary_name":"squid-common"},{"binary_version":"4.10-1ubuntu1.13+esm2","binary_name":"squid-purge"},{"binary_version":"4.10-1ubuntu1.13+esm2","binary_name":"squidclient"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2019/UBUNTU-CVE-2019-12522.json"}},{"package":{"name":"squid","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/squid@5.9-0ubuntu0.22.04.5?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.13-10ubuntu5","5.2-1ubuntu1","5.2-1ubuntu3","5.2-1ubuntu4","5.2-1ubuntu4.1","5.2-1ubuntu4.2","5.2-1ubuntu4.3","5.7-0ubuntu0.22.04.1","5.7-0ubuntu0.22.04.2","5.7-0ubuntu0.22.04.3","5.7-0ubuntu0.22.04.4","5.9-0ubuntu0.22.04.1","5.9-0ubuntu0.22.04.2","5.9-0ubuntu0.22.04.3","5.9-0ubuntu0.22.04.4","5.9-0ubuntu0.22.04.5"],"ecosystem_specific":{"binaries":[{"binary_version":"5.9-0ubuntu0.22.04.5","binary_name":"squid"},{"binary_version":"5.9-0ubuntu0.22.04.5","binary_name":"squid-cgi"},{"binary_version":"5.9-0ubuntu0.22.04.5","binary_name":"squid-common"},{"binary_version":"5.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