X.Org X server before 1.13.4 and 1.4.x before 1.14.1 does not properly restrict access to input events when adding a new hot-plug device, which might allow physically proximate attackers to obtain sensitive information, as demonstrated by reading passwords from a tty. Per http://www.ubuntu.com/usn/USN-1803-1/
"A security issue affects these releases of Ubuntu and its derivatives:
Ubuntu 12.10
Ubuntu 12.04 LTS
Ubuntu 11.10
Ubuntu 10.04 LTS"
Publication date: Tue, 14 May 2013 04:55:00 +0000