ImageMagick is "a suite of image manipulation tools (animate, composite, conjure, convert, display, identify, import, mogrify and montage) that are sometimes used by other applications for processing image files". Remote exploitation of an off-by-one vulnerability in ImageMagick, as included in various vendors' operating system distributions, allows attackers to execute arbitrary code.

http://www.securiteam.com/unixfocus/5JP0M1FMKG.html