USN-4966-1: libx11 vulnerability

Releases

• Ubuntu 21.04
• Ubuntu 20.10
• Ubuntu 20.04 LTS
• Ubuntu 18.04 ESM

Packages

• libx11 - X11 client-side library

Details

It was discovered that libx11 incorrectly validated certain parameter
lengths. A remote attacker could possibly use this issue to trick libx11
into emitting extra X protocol requests.

Update instructions

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

Ubuntu 21.04

• libx11-6 - 2:1.7.0-2ubuntu0.1

Ubuntu 20.10

• libx11-6 - 2:1.6.12-1ubuntu0.1

Ubuntu 20.04

• libx11-6 - 2:1.6.9-2ubuntu1.2

Ubuntu 18.04

• libx11-6 - 2:1.6.4-3ubuntu0.4

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

References

• CVE-2021-31535

Related notices

• USN-4966-2: libx11-data, libx11-6, libx11-xcb1, libx11-dev, libx11-doc, libx11-xcb-dev, libx11-6-udeb, libx11