1. Ubuntu Security Notices
  2. USN-4614-1

USN-4614-1: GDM vulnerability

Publication date

3 November 2020

Overview

GDM could be made to create privileged users.

Releases

Packages

  • gdm3 - GNOME Display Manager

Details

Kevin Backhouse discovered that GDM incorrectly launched the initial setup
tool when the accountsservice daemon was not reachable. A local attacker
able to cause accountsservice to crash or stop responding could trick GDM
into launching the initial setup tool and create a privileged user.

Kevin Backhouse discovered that GDM incorrectly launched the initial setup
tool when the accountsservice daemon was not reachable. A local attacker
able to cause accountsservice to crash or stop responding could trick GDM
into launching the initial setup tool and create a privileged user.

Update instructions

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

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
20.10 groovy gdm3 –  3.38.1-2ubuntu1.1
20.04 focal gdm3 –  3.36.3-0ubuntu0.20.04.2
18.04 bionic gdm3 –  3.28.3-0ubuntu18.04.6

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References

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