Information disclosure in Ffmpeg

CVE-2021-3566

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).

Vulnerability class: Information Disclosure

EPSS: 0.009 (55.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-3566?
CVE-2021-3566 is a medium-severity vulnerability in Ffmpeg, classified under Information Disclosure. CVSS score: 5.5/10. Published 2021-08-05.
How severe is CVE-2021-3566?
Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2021-3566 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.