Buffer Overflow vulnerability in FFmpeg 4.2 in mov_write_video_tag due to the out of bounds in libavformat/movenc.c, which could let a remote malicious user obtain sensitive information, cause a Denial of Service, or execute arbitrary code.
https://www.debian.org/security/2021/dsa-4990
https://trac.ffmpeg.org/ticket/8190
https://lists.debian.org/debian-lts-announce/2021/08/msg00018.html