Aaron Plattner discovered that the Composite extension did not correctly calculate the size of buffers when copying between different bit depths. An authenticated user could exploit this to execute arbitrary code with root privileges.
The problem can be corrected by updating your system to the following package versions:
18 September 2007
A security issue affects these releases of Ubuntu and its derivatives:
Aaron Plattner discovered that the Composite extension did not correctly calculate the size of buffers when copying between different bit depths. An authenticated user could exploit this to execute arbitrary code with root privileges.
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.
After a standard system upgrade you need to restart your session to effect the necessary changes.
Vulmon