feh: Arbitrary remote code execution

Background

feh is an X11 image viewer aimed mostly at console users.

Description

Tobias Stoeckmann discovered it was possible to trigger an out-of-boundary heap write with the image viewer feh while receiving an IPC message.

Impact

A remote attacker, pretending to be the E17 window manager, could possibly trigger an out-of-boundary heap write in feh while receiving an IPC message. This could result in execution of arbitrary code with the privileges of the process or a Denial of Service condition.

Workaround

There is no known workaround at this time.

Resolution

All feh users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=media-gfx/feh-2.18.3"