{"id":"UBUNTU-CVE-2018-6954","details":"systemd-tmpfiles in systemd through 237 mishandles symlinks present in non-terminal path components, which allows local users to obtain ownership of arbitrary files via vectors involving creation of a directory and a file under that directory, and later replacing that directory with a symlink. This occurs even if the fs.protected_symlinks sysctl is turned on.","modified":"2026-01-30T02:07:00.772776Z","published":"2018-02-13T00:00:00Z","related":["USN-3816-1","USN-3816-2"],"upstream":["CVE-2018-6954"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2018-6954"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-3816-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-3816-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2018-6954"}],"affected":[{"package":{"name":"systemd","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/systemd@229-4ubuntu21.15?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"229-4ubuntu21.15"}]}],"versions":["225-1ubuntu9","227-2ubuntu1","227-2ubuntu2","228-1ubuntu2","228-2ubuntu1","228-2ubuntu2","228-3ubuntu1","228-4ubuntu1","228-4ubuntu2","228-5ubuntu1","228-5ubuntu2","228-5ubuntu3","228-6ubuntu1","229-1ubuntu2","229-1ubuntu4","229-2ubuntu1","229-3ubuntu1","229-3ubuntu2","229-4ubuntu1","229-4ubuntu4","229-4ubuntu5","229-4ubuntu6","229-4ubuntu7","229-4ubuntu8","229-4ubuntu10","229-4ubuntu11","229-4ubuntu12","229-4ubuntu13","229-4ubuntu16","229-4ubuntu17","229-4ubuntu19","229-4ubuntu20","229-4ubuntu21","229-4ubuntu21.1","229-4ubuntu21.2","229-4ubuntu21.3","229-4ubuntu21.4","229-4ubuntu21.5","229-4ubuntu21.6","229-4ubuntu21.8","229-4ubuntu21.9","229-4ubuntu21.10"],"ecosystem_specific":{"binaries":[{"binary_version":"229-4ubuntu21.15","binary_name":"libnss-myhostname"},{"binary_version":"229-4ubuntu21.15","binary_name":"libnss-mymachines"},{"binary_version":"229-4ubuntu21.15","binary_name":"libnss-resolve"},{"binary_version":"229-4ubuntu21.15","binary_name":"libpam-systemd"},{"binary_version":"229-4ubuntu21.15","binary_name":"libsystemd-dev"},{"binary_version":"229-4ubuntu21.15","binary_name":"libsystemd0"},{"binary_version":"229-4ubuntu21.15","binary_name":"libudev-dev"},{"binary_version":"229-4ubuntu21.15","binary_name":"libudev1"},{"binary_version":"229-4ubuntu21.15","binary_name":"systemd"},{"binary_version":"229-4ubuntu21.15","binary_name":"systemd-container"},{"binary_version":"229-4ubuntu21.15","binary_name":"systemd-coredump"},{"binary_version":"229-4ubuntu21.15","binary_name":"systemd-journal-remote"},{"binary_version":"229-4ubuntu21.15","binary_name":"systemd-sysv"},{"binary_version":"229-4ubuntu21.15","binary_name":"udev"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-6954.json"}},{"package":{"name":"systemd","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/systemd@237-3ubuntu10.9?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"237-3ubuntu10.9"}]}],"versions":["234-2ubuntu12","235-2ubuntu3","235-3ubuntu2","235-3ubuntu3","237-3ubuntu3","237-3ubuntu4","237-3ubuntu6","237-3ubuntu7","237-3ubuntu8","237-3ubuntu10","237-3ubuntu10.2","237-3ubuntu10.3","237-3ubuntu10.4","237-3ubuntu10.6"],"ecosystem_specific":{"binaries":[{"binary_version":"237-3ubuntu10.9","binary_name":"libnss-myhostname"},{"binary_version":"237-3ubuntu10.9","binary_name":"libnss-mymachines"},{"binary_version":"237-3ubuntu10.9","binary_name":"libnss-resolve"},{"binary_version":"237-3ubuntu10.9","binary_name":"libnss-systemd"},{"binary_version":"237-3ubuntu10.9","binary_name":"libpam-systemd"},{"binary_version":"237-3ubuntu10.9","binary_name":"libsystemd-dev"},{"binary_version":"237-3ubuntu10.9","binary_name":"libsystemd0"},{"binary_version":"237-3ubuntu10.9","binary_name":"libudev-dev"},{"binary_version":"237-3ubuntu10.9","binary_name":"libudev1"},{"binary_version":"237-3ubuntu10.9","binary_name":"systemd"},{"binary_version":"237-3ubuntu10.9","binary_name":"systemd-container"},{"binary_version":"237-3ubuntu10.9","binary_name":"systemd-coredump"},{"binary_version":"237-3ubuntu10.9","binary_name":"systemd-journal-remote"},{"binary_version":"237-3ubuntu10.9","binary_name":"systemd-sysv"},{"binary_version":"237-3ubuntu10.9","binary_name":"systemd-tests"},{"binary_version":"237-3ubuntu10.9","binary_name":"udev"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-6954.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},{"type":"CVSS_V3","score":"CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}]}