Sudo could allow users to run arbitrary programs as the administrator.
It was discovered that sudo incorrectly handled network masks when using Host and Host_List. A local user who is listed in sudoers may be allowed to run commands on unintended hosts when IPv4 network masks are used to grant access. A local attacker could exploit this to bypass intended access restrictions. Host and Host_List are not used in the default installation of Ubuntu.
16 May 2012
A security issue affects these releases of Ubuntu and its derivatives:
Sudo could allow users to run arbitrary programs as the administrator.
It was discovered that sudo incorrectly handled network masks when using Host and Host_List. A local user who is listed in sudoers may be allowed to run commands on unintended hosts when IPv4 network masks are used to grant access. A local attacker could exploit this to bypass intended access restrictions. Host and Host_List are not used in the default installation of 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 update will make all the necessary changes.