Multiple integer overflows in CamlImages 2.2 and earlier might allow context-dependent attackers to execute arbitrary code via a crafted PNG image with large width and height values that trigger a heap-based buffer overflow in the (1) read_png_file or (2) read_png_file_as_rgb24 function.
http://www.vupen.com/english/advisories/2009/1874
http://www.securityfocus.com/bid/35556
http://www.securityfocus.com/archive/1/504696/100/0/threaded
http://www.ocert.org/advisories/ocert-2009-009.html