ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 7.1.2-15 and 6.9.13-40, a NULL pointer dereference in ClonePixelCacheRepository allows a remote attacker to crash any application linked against ImageMagick by supplying a crafted image file, resulting in denial of service. Versions 7.1.2-15 and 6.9.13-40 contain a patch.