ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to ImageMagick versions 6.9.13-28 and 7.1.2-2, a format string bug vulnerability exists in InterpretImageFilename function where user input is directly passed to FormatLocaleString without proper sanitization. An attacker can overwrite arbitrary memory regions, enabling a wide range of attacks from heap overflow to remote code execution. This issue has been patched in versions 6.9.13-28 and 7.1.2-2.
Any condition where the attacker has the ability to write an arbitrary value to an arbitrary location, often as the result of a buffer overflow.