DistUpgrade/DistUpgradeFetcherCore.py in Update Manager before 1:0.87.31.1, 1:0.134.x before 1:0.134.11.1, 1:0.142.x before 1:0.142.23.1, 1:0.150.x before 1:0.150.5.1, and 1:0.152.x before 1:0.152.25.5 on Ubuntu 8.04 through 11.10 does not verify the GPG signature before extracting an upgrade tarball, which allows man-in-the-middle attackers to (1) create or overwrite arbitrary files via a directory traversal attack using a crafted tar file, or (2) bypass authentication via a crafted meta-release file.

DistUpgrade/DistUpgradeViewKDE.py in Update Manager before 1:0.87.31.1, 1:0.134.x before 1:0.134.11.1, 1:0.142.x before 1:0.142.23.1, 1:0.150.x before 1:0.150.5.1, and 1:0.152.x before 1:0.152.25.5 does not properly create temporary files, which allows local users to obtain the XAUTHORITY file content for a user via a symlink attack on the temporary file.

DistUpgrade/DistUpgradeMain.py in Update Manager, as used by Ubuntu 12.04 LTS, 11.10, and 11.04, uses weak permissions for (1) apt-clone_system_state.tar.gz and (2) system_state.tar.gz, which allows local users to obtain repository credentials.