In GraphicsMagick 1.4 snapshot-20181209 Q8 on 32-bit platforms, there is a heap-based buffer over-read in the ReadBMPImage function of bmp.c, which allows attackers to cause a denial of service via a crafted bmp image file. This only affects GraphicsMagick installations with customized BMP limits.
https://www.debian.org/security/2020/dsa-4640
https://usn.ubuntu.com/4207-1/
https://sourceforge.net/p/graphicsmagick/bugs/582/
https://lists.debian.org/debian-lts-announce/2018/12/msg00018.html
http://www.securityfocus.com/bid/106229
http://hg.graphicsmagick.org/hg/GraphicsMagick/rev/648e3977a293