The Magick_png_malloc function in coders/png.c in GraphicsMagick 6.7.8-6 does not use the proper variable type for the allocation size, which might allow remote attackers to cause a denial of service (crash) via a crafted PNG file that triggers incorrect memory allocation.
https://exchange.xforce.ibmcloud.com/vulnerabilities/77259
https://euvd.enisa.europa.eu/vulnerability/EUVD-2012-3405
https://bugzilla.redhat.com/show_bug.cgi?id=844105
http://www.securityfocus.com/bid/54716
http://www.mandriva.com/security/advisories?name=MDVSA-2012:165
http://secunia.com/advisories/50090
http://lists.opensuse.org/opensuse-updates/2013-03/msg00102.html
http://graphicsmagick.hg.sourceforge.net/hgweb/graphicsmagick/graphicsmagick/rev/d6e469d02cd2