In coders/xbm.c in ImageMagick 7.0.6-1 Q16, a DoS in ReadXBMImage() due to lack of an EOF (End of File) check might cause huge CPU consumption. When a crafted XBM file, which claims large rows and columns fields in the header but does not contain sufficient backing data, is provided, the loop over the rows would consume huge CPU resources, since there is no EOF check inside the loop.
https://usn.ubuntu.com/3681-1/
https://security.gentoo.org/glsa/201711-07
https://lists.debian.org/debian-lts-announce/2020/09/msg00007.html
https://lists.debian.org/debian-lts-announce/2019/05/msg00015.html
https://github.com/ImageMagick/ImageMagick/commit/d9a8234d211da30baf9526fbebe9a8438ea7e11c