decode_frame in libavcodec/exr.c in FFmpeg 4.3.1 has an out-of-bounds write because of errors in calculations of when to perform memset zero operations.
https://www.debian.org/security/2021/dsa-4990
https://security.gentoo.org/glsa/202105-24
https://lists.debian.org/debian-lts-announce/2021/01/msg00026.html
https://github.com/FFmpeg/FFmpeg/commit/b0a8b40294ea212c1938348ff112ef1b9bf16bb3
https://github.com/FFmpeg/FFmpeg/commit/3e5959b3457f7f1856d997261e6ac672bba49e8b