In a security notice, Canonical has published details about a Mesa vulnerability for its Ubuntu 12.04 LTS (Precise Pangolin) operating system.
According to Canonical, Mesa could have been made to crash or run programs, if it processed specially crafted data.
It was discovered that Mesa incorrectly handled certain arrays. An attacker could have used this issue to cause Mesa to crash, resulting in a denial of service, or possibly execute arbitrary code.
For a more detailed description of the security problems, you can visit Canonical's security notification.
Users can simply fix the security flaw by upgrading the operating systems to the latest Mesa-related packages
A normal system update, executed with the Update Manager, will implement all the necessary changes, but you will also need to reboot the computer.
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.