Tk: Buffer overflow

Background

Tk is a toolkit for creating graphical user interfaces.

Description

Reinhard Max discovered a boundary error in Tk when processing an interlaced GIF with two frames where the second is smaller than the first one.

Impact

A remote attacker could entice a user to open a specially crafted GIF image with a Tk-based software, possibly resulting in the execution of arbitrary code with the privileges of the user running the application.

Workaround

There is no known workaround at this time.

Resolution

All Tk users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=dev-lang/tk-8.4.15-r1"