Harald Koenig discovered that sudo did not correctly handle certain privilege changes when handling groups. If a local attacker belonged to a group included in a “RunAs” list in the /etc/sudoers file, that user could gain root privileges. This was not an issue for the default sudoers file shipped with Ubuntu.
The problem can be corrected by updating your system to the following package versions:
17 February 2009
A security issue affects these releases of Ubuntu and its derivatives:
Harald Koenig discovered that sudo did not correctly handle certain privilege changes when handling groups. If a local attacker belonged to a group included in a “RunAs” list in the /etc/sudoers file, that user could gain root privileges. This was not an issue for the default sudoers file shipped with Ubuntu.
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 upgrade is sufficient to effect the necessary changes.
Vulmon