ImageMagick: Format string vulnerability

Background

ImageMagick is an application suite to manipulate and convert images. It is often used as a utility backend by web applications like forums, content management systems or picture galleries.

Description

The SetImageInfo function was found vulnerable to a format string mishandling. Daniel Kobras discovered that the handling of “%”-escaped sequences in filenames passed to the function is inadequate. This is a new vulnerability that is not addressed by GLSA 200503-11.

Impact

By feeding specially crafted file names to ImageMagick, an attacker can crash the program and possibly execute arbitrary code with the privileges of the user running ImageMagick.

Workaround

There is no known workaround at this time.

Resolution

All ImageMagick users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=media-gfx/imagemagick-6.2.5.5"