USN-4269-1: systemd vulnerabilities

Releases

• Ubuntu 19.10
• Ubuntu 18.04 ESM
• Ubuntu 16.04 ESM

Packages

• systemd - system and service manager

Details

It was discovered that systemd incorrectly handled certain PIDFile files.
A local attacker could possibly use this issue to trick systemd into
killing privileged processes. This issue only affected Ubuntu 16.04 LTS.
(CVE-2018-16888)

It was discovered that systemd incorrectly handled certain udevadm trigger
commands. A local attacker could possibly use this issue to cause systemd
to consume resources, leading to a denial of service. (CVE-2019-20386)

Jann Horn discovered that systemd incorrectly handled services that use the
DynamicUser property. A local attacker could possibly use this issue to
access resources owned by a different service in the future. This issue
only affected Ubuntu 18.04 LTS. (CVE-2019-3843, CVE-2019-3844)

Tavis Ormandy discovered that systemd incorrectly handled certain Polkit
queries. A local attacker could use this issue to cause systemd to crash,
resulting in a denial of service, or possibly execute arbitrary code and
escalate privileges. (CVE-2020-1712)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 19.10

• systemd - 242-7ubuntu3.6

Ubuntu 18.04

• systemd - 237-3ubuntu10.38

Ubuntu 16.04

• systemd - 229-4ubuntu21.27

After a standard system update you need to reboot your computer to make
all the necessary changes.

References

• CVE-2018-16888
• CVE-2019-20386
• CVE-2019-3843
• CVE-2019-3844
• CVE-2020-1712