Update Manager could be made to overwrite files as the administrator.
David Black discovered that Update Manager incorrectly extracted the downloaded upgrade tarball before verifying its GPG signature. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could potentially be used to replace arbitrary files. (CVE-2011-3152)
28 November 2011
A security issue affects these releases of Ubuntu and its derivatives:
Update Manager could be made to overwrite files as the administrator.
David Black discovered that Update Manager incorrectly extracted the downloaded upgrade tarball before verifying its GPG signature. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could potentially be used to replace arbitrary files. (CVE-2011-3152)
David Black discovered that Update Manager created a temporary directory in an insecure fashion. A local attacker could possibly use this flaw to read the XAUTHORITY file of the user performing the upgrade. (CVE-2011-3154)
This update also adds a hotfix to Update Notifier to handle cases where the upgrade is being performed from CD media.
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