The functions ReadDCMImage in coders/dcm.c, ReadPWPImage in coders/pwp.c, ReadCALSImage in coders/cals.c, and ReadPICTImage in coders/pict.c in ImageMagick 7.0.8-4 do not check the return value of the fputc function, which allows remote attackers to cause a denial of service via a crafted image file.
https://usn.ubuntu.com/3785-1/
https://lists.debian.org/debian-lts-announce/2020/09/msg00007.html
https://lists.debian.org/debian-lts-announce/2018/10/msg00002.html
https://github.com/ImageMagick/ImageMagick/issues/1199
https://github.com/ImageMagick/ImageMagick/commit/6b6bff054d569a77973f2140c0e86366e6168a6c