Ubuntu Update for Linux kernel vulnerabilities USN-1385-1
Please Install the Updated 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.
apt on Ubuntu 11.04