A heap-based Buffer Overflow vulnerability in FFmpeg 4.2 at libavcodec/get_bits.h when writing .mov files, which might lead to memory corruption and other potential consequences.
https://www.debian.org/security/2021/dsa-4990
https://trac.ffmpeg.org/ticket/8183
https://lists.debian.org/debian-lts-announce/2021/08/msg00018.html