14 DAY TRIAL // Details about a cgmanager vulnerability in its Ubuntu 14.10 and Ubuntu 14.04 LTS operating systems have been revealed by Canonical. This is not a serious issue, but users should upgrade their systems as soon as possible.
A number of important fixes have been released for the supported Ubuntu systems, and the changes to cgmanager are among these updates. From the looks of it, cgmanager could have exposed sensitive information or devices to containers running on the system.
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" is noted in the Canonical's security notification. Users have been advised to upgrade their systems as soon as possible.
The problem can be fixed by upgrading the system(s) to the latest cgmanager packages specific to each distribution. To apply the patch, run the Update Manager application.
If you don't want to use the Software Updater, you can do this from a terminal. Open a terminal and enter the following commands:
sudo apt-get dist-upgrade