USN-3816-2: systemd vulnerability
19 November 2018
systemd-tmpfiles could be made to change ownership of arbitrary files.
Releases
Packages
- systemd - system and service manager
Details
USN-3816-1 fixed several vulnerabilities in systemd. However, the fix for
CVE-2018-6954 was not sufficient. This update provides the remaining fixes.
We apologize for the inconvenience.
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)
Update instructions
The problem can be corrected by updating your system to the following package versions:
Ubuntu 18.10
Ubuntu 18.04
Ubuntu 16.04
After a standard system update you need to reboot your computer to make
all the necessary changes.
References
Related notices
- USN-3816-1: libnss-systemd, systemd-sysv, libnss-myhostname, libpam-systemd, systemd, systemd-container, libnss-resolve, udev, libudev-dev, systemd-journal-remote, libudev1-udeb, systemd-tests, libsystemd-dev, libudev1, systemd-coredump, libsystemd0, libnss-mymachines, udev-udeb