=========================================================================Ubuntu Security Notice USN-5191-1
December 14, 2021

flatpak vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 21.10
- Ubuntu 21.04
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

A system hardening measure could be bypassed.

Software Description:
- flatpak: Application deployment framework for desktop apps

Details:

It was discovered that Flatpak incorrectly handled certain AF_UNIX sockets.
An attacker could use this to specially craft a Flatpak application that
could escape sandbox confinement.

Update instructions:

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

Ubuntu 21.10:
  flatpak                         1.10.2-3ubuntu0.1
  libflatpak0                     1.10.2-3ubuntu0.1

Ubuntu 21.04:
  flatpak                         1.10.2-1ubuntu1.1
  libflatpak0                     1.10.2-1ubuntu1.1

Ubuntu 20.04 LTS:
  flatpak                         1.6.5-0ubuntu0.4
  libflatpak0                     1.6.5-0ubuntu0.4

Ubuntu 18.04 LTS:
  flatpak                         1.0.9-0ubuntu0.4
  libflatpak0                     1.0.9-0ubuntu0.4

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-5191-1
  CVE-2021-41133

Package Information:
  https://launchpad.net/ubuntu/+source/flatpak/1.10.2-3ubuntu0.1
  https://launchpad.net/ubuntu/+source/flatpak/1.10.2-1ubuntu1.1
  https://launchpad.net/ubuntu/+source/flatpak/1.6.5-0ubuntu0.4
  https://launchpad.net/ubuntu/+source/flatpak/1.0.9-0ubuntu0.4