An attacker could trick APT into installing altered packages.
Simon Ruderich discovered that APT incorrectly handled repositories that use InRelease files. The default Ubuntu repositories do not use InRelease files, so this issue only affected third-party repositories. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could potentially be used to install altered packages.
6 March 2012
A security issue affects these releases of Ubuntu and its derivatives:
An attacker could trick APT into installing altered packages.
Simon Ruderich discovered that APT incorrectly handled repositories that use InRelease files. The default Ubuntu repositories do not use InRelease files, so this issue only affected third-party repositories. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could potentially be used to install altered packages.
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.
Vulmon