Ubuntu Update for apt USN-2246-1

Solution
Please Install the Updated Packages.
Insight
Jakub Wilk discovered that APT did not correctly validate signatures when downloading source packages. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could potentially be used to install altered source packages.
Affected
apt on Ubuntu 14.04 LTS , Ubuntu 13.10 , Ubuntu 12.04 LTS , Ubuntu 10.04 LTS
References