CVE-2021-3566

mediumpriority · track · 22EPSS 0.009 · 59 %ileDEEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.88% (59th) EPSS
CVSS 4.3 · medium
Is it mine?
14 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

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).

01

cvss

Technical severity, 0–10. One row per scoring source.

6.5
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04.3mediumAV:N/AC:M/Au:N/C:P/I:N/A:Nprimary · NVD / NIST USexploitability 8.6 · impact 2.9
v3.15.5mediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:Nprimary · NVD / NIST USexploitability 1.8 · impact 3.6
v3.16.5mediumAV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:Nsecondary · FSTEC (BDU) RU
v3.15.1mediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)
02

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-200USCWE-200US
03

affected products (14)

Products and version ranges known to be affected.

04

advisories (1)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2023-0010ffmpeg: Schwachstelle ermöglicht Offenlegung von InformationenDeutsch2021-08-05csaf · cert_bundDE

    Ein Angreifer kann eine Schwachstelle in ffmpeg ausnutzen, um Informationen offenzulegen.

05

also known as (4)

Other names and identifiers for this entity.

06

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundnvdNVDCVE.orgMITRE
published 2021-08-05modified 2026-06-17
07

references (11)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan