Nova could be made to crash the system if instances used a specially crafted image.
Loganathan Parthipan discovered that Nova did not verify the size of QCOW2 instance storage. An authenticated attacker could exploit this to cause a denial of service by creating an image with a large virtual size with little data, then filling the virtual disk.
16 May 2013
A security issue affects these releases of Ubuntu and its derivatives:
Nova could be made to crash the system if instances used a specially crafted image.
Loganathan Parthipan discovered that Nova did not verify the size of QCOW2 instance storage. An authenticated attacker could exploit this to cause a denial of service by creating an image with a large virtual size with little data, then filling the virtual disk.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.