OptiPNG: User-assisted execution of arbitrary code

Background

OptiPNG is a PNG optimizer that recompresses image files to a smaller size, without losing any information.

Description

Roy Tam reported a use-after-free vulnerability in the GIFReadNextExtension() function in lib/pngxtern/gif/gifread.c leading to a memory corruption when reading a GIF image.

Impact

A remote attacker could entice a user to process a specially crafted GIF image, possibly resulting in the execution of arbitrary code with the privileges of the user running the application, or a Denial of Service.

Workaround

There is no known workaround at this time.

Resolution

All OptiPNG users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=media-gfx/optipng-0.6.2-r1"