Ubuntu 16.04 LTS : systemd regression (USN-3816-3)
Critical Nessus Plugin ID 119253
SynopsisThe remote Ubuntu host is missing a security-related patch.
DescriptionUSN-3816-1 fixed vulnerabilities in systemd. The fix for CVE-2018-6954 caused a regression in systemd-tmpfiles when running Ubuntu inside a container on some older kernels. This issue only affected Ubuntu 16.04 LTS. In order to continue to support this configuration, the fixes for CVE-2018-6954 have been reverted.
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Original advisory details :
Jann Horn discovered that unit_deserialize incorrectly handled status messages above a certain length. A local attacker could potentially exploit this via NotifyAccess to inject arbitrary state across re-execution and obtain root privileges. (CVE-2018-15686)
Jann Horn discovered a race condition in chown_one(). A local attacker could potentially exploit this by setting arbitrary permissions on certain files to obtain root privileges. This issue only affected Ubuntu 18.04 LTS and Ubuntu 18.10. (CVE-2018-15687)
It was discovered that systemd-tmpfiles mishandled symlinks in non-terminal path components. A local attacker could potentially exploit this by gaining ownership of certain files to obtain root privileges. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2018-6954).
Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpdate the affected systemd package.