USN-2451-1: cgmanager vulnerability

6 January 2015

cgmanager vulnerability

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

  • Ubuntu 14.10
  • Ubuntu 14.04 LTS


cgmanager could be made to expose sensitive information or devices to containers running on the system.

Software Description

  • cgmanager - Central cgroup manager daemon


Serge Hallyn discovered that cgmanager did not consistently enforce proper nesting when modifying cgroup properties. A local attacker in a privileged container could use this to set cgroup values for all cgroups.

Update instructions

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

Ubuntu 14.10
cgmanager - 0.32-4ubuntu1.1
Ubuntu 14.04 LTS
cgmanager - 0.24-0ubuntu7.1

To update your system, please follow these instructions:

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