ImageMagick has a heap buffer over-read via 32-bit integer overflow in MAT decoder

ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 7.1.2-16 and 6.9.13-41, MAT decoder uses 32-bit arithmetic due to incorrect parenthesization resulting in a heap over-read. This vulnerability is fixed in 7.1.2-16 and 6.9.13-41.