ImageMagick has a heap use-after-free in the MSL encoder

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, a heap-use-after-free vulnerability exists in the MSL encoder, where a cloned image is destroyed twice. The MSL coder does not support writing MSL so the write capability has been removed. This vulnerability is fixed in 7.1.2-16 and 6.9.13-41.