source: http://www.securityfocus.com/bid/13351/info

A remotely exploitable client-side buffer-overflow vulnerability affects ImageMagick. This issue occurs because the application fails to properly validate the length of user-supplied strings before copying them into static process buffers.

An attacker may exploit this issue to cause the affected application to crash, potentially destroying unsaved data, ultimately denying service to legitimate users. 

perl -e 'print "P7\n1\n1 1\n1"' > vuln.pnm