A type conversion flaw leading to an out-of-bounds heap buffer read was found in the way libpng, a library of functions for manipulation PNG image format files, performed expansion of certain iCCP, iTXt, and zTXt PNG image file chunks.

A remote attacker could provide a specially-crafted Portable Network Graphics (PNG) image file, which once opened in an application, linked against libpng, could lead to denial of service or in some cases, execution of arbitrary code with permission of the user running such an application.

Upstream patch: http://libpng.git.sourceforge.net/git/gitweb.cgi?p=libpng/libpng;a=commitdiff;h=a8c319a2b281af68f7ca0e2f9a28ca57b44ceb2b#patch3