In coders/bmp.c in ImageMagick before 7.0.8-16, an input file can result in an infinite loop and hang, with high CPU and memory consumption. Remote attackers could leverage this vulnerability to cause a denial of service via a crafted file.
https://usn.ubuntu.com/4034-1/
https://lists.debian.org/debian-lts-announce/2020/08/msg00030.html
https://github.com/ImageMagick/ImageMagick/commit/db0add932fb850d762b02604ca3053b7d7ab6deb