USN-1262-1: Light Display Manager vulnerabilities

15 November 2011

lightdm vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 11.10

Summary

Several security issues were fixed in Light Display Manager.

Software Description

  • lightdm - Display Manager

Details

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)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 11.10
liblightdm-gobject-1-0 - 1.0.6-0ubuntu1.1
liblightdm-qt-1-0 - 1.0.6-0ubuntu1.1
lightdm - 1.0.6-0ubuntu1.1

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

After a standard system update you need to reboot your computer to make all the necessary changes.

References