USN-3816-2: systemd vulnerability
systemd vulnerability
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 18.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
Summary
systemd-tmpfiles could be made to change ownership of arbitrary files.
Software Description
- 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
- systemd – 239-7ubuntu10.4
- Ubuntu 18.04 LTS
- systemd – 237-3ubuntu10.9
- Ubuntu 16.04 LTS
- systemd – 229-4ubuntu21.9
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to reboot your computer to make
all the necessary changes.
References
Source: USN-3816-2: systemd vulnerability
