CVE-2021-3566: Prior to ffmpeg version 4.3, the tty demuxer did not have a 'read_probe' function assigned to it

Description

Prior to ffmpeg version 4.3, the tty demuxer did not have a 'read_probe' function assigned to it. By crafting a legitimate "ffconcat" file that references an image, followed by a file the triggers the tty demuxer, the contents of the second file will be copied into the output file verbatim (as long as the `-vcodec copy` option is passed to ffmpeg).

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Attack vector

Local

Complexity

Low

Privileges

None

User interaction

Required

Confidentiality

High

Integrity

None

Availability

None

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)0.9% · higher than 59% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

DL

Debian Linux · Debian

9.0 · source: NVD

FF

Ffmpeg · Ffmpeg

before 4.3 · source: NVD