A GNOME Shell security update has been released for Ubuntu Linux 20.04 LTS.

USN-4464-1: GNOME Shell vulnerability

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Ubuntu Security Notice USN-4464-1
August 18, 2020

gnome-shell vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS

Summary:

The system could be made to expose sensitive information.

Software Description:
- gnome-shell: graphical shell for the GNOME desktop

Details:

It was discovered that GNOME Shell incorrectly handled the login screen
password dialog. Sensitive information could possibly be exposed during
user logout.

Update instructions:

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

Ubuntu 20.04 LTS:
gnome-shell 3.36.4-1ubuntu1~20.04.2

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

References:
  https://usn.ubuntu.com/4464-1
CVE-2020-17489

Package Information:
  https://launchpad.net/ubuntu/+source/gnome-shell/3.36.4-1ubuntu1~20.04.2