ImageMagick CLAHE : Unsigned underflow and division-by-zero lead to OOB pointer arithmetic and process crash (DoS)

ImageMagick is a software suite to create, edit, compose, or convert bitmap images. ImageMagick versions prior to 7.1.2-8 are vulnerable to denial-of-service due to unsigned integer underflow and division-by-zero in the CLAHEImage function. When tile width or height is zero, unsigned underflow occurs in pointer arithmetic, leading to out-of-bounds memory access, and division-by-zero causes immediate crashes. This issue has been patched in version 7.1.2-8.