Ubuntu Update for lightdm USN-1262-1

Summary
Ubuntu Update for Linux kernel vulnerabilities USN-1262-1
Solution
Please Install the Updated Packages.
Insight
It was discovered that Light Display Manager incorrectly handled privileges when reading .dmrc files. A local attacker could exploit this issue to read arbitrary configuration files, bypassing intended permissions. (CVE-2011-3153) It was discovered that Light Display Manager incorrectly handled links when adjusting permissions on .Xauthority files. A local attacker could exploit this issue to access arbitrary files, and possibly obtain increased privileges. In the default Ubuntu installation, this would be prevented by the Yama link restrictions. (CVE-2011-4105)
Affected
lightdm on Ubuntu 11.10