Heap-based buffer overflow in the ReadSFWImage function in coders/sfw.c in ImageMagick 7.0.6-8 allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted file.
https://github.com/ImageMagick/ImageMagick/issues/682
https://security.gentoo.org/glsa/201711-07
https://usn.ubuntu.com/3681-1/