Every CVE Search/ Get API key

CVE-2021-3566

Prior to ffmpeg version 4.3, the tty demuxer did not have a 'read_probe' function assigned to it....

5.5 MediumFix available

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).

Attack profile

How easy it is to exploit

Attack vector
Local
Complexity
Low
Privileges needed
None
User interaction
Required

What an attacker can affect

Confidentiality
High
Integrity
None
Availability
None

Exploit likelihood

0.88%Up 0.5 points since Aug 6, 2021
90%50%10%1%

What each source reports

NVD Score used 5.5

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).

Record
CVE-2021-3566
CVSS 3.1
5.5 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CVSS 2.0
4.3 MediumAV:N/AC:M/Au:N/C:P/I:N/A:N
Weakness
CWE-200
Updated
2026-11-02
CVE List No score

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).

Record
CVE-2021-3566
Weakness
CWE-200
Updated
2026-11-02
EUVDEUVD-2021-26876 No score

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).

Record
EUVD-2021-26876
Updated
2026-11-03
GitHub AdvisoriesGHSA-742p-65hp-7vgf 5.5

Prior to ffmpeg version 4.3, the tty demuxer did not have a 'read_probe' function assigned to it....

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).

Record
GHSA-742p-65hp-7vgf
CVSS 3.1
5.5 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Updated
2026-11-02
OSV 5.5

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).

Record
CVE-2021-3566
CVSS 3.1
5.5 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Updated
2026-11-07
OSVDEBIAN-CVE-2021-3566 5.5

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).

Record
DEBIAN-CVE-2021-3566
CVSS 3.1
5.5 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Updated
2026-11-02
Show 6 moreShow less
OSVJLSEC-2025-116 5.5

Prior to ffmpeg version 4.3, the tty demuxer did not have a '`read_probe`' function assigned to it

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).

Record
JLSEC-2025-116
CVSS 3.1
5.5 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CVSS 2.0
4.3 MediumAV:N/AC:M/Au:N/C:P/I:N/A:N
Updated
2026-11-02
OSVUBUNTU-CVE-2021-3566 5.5

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).

Record
UBUNTU-CVE-2021-3566
CVSS 3.1
5.5 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Updated
2026-11-02
OSVopenSUSE-SU-2021:3521-1 No score

Security update for ffmpeg

This update for ffmpeg fixes the following issues:

  • CVE-2021-3566: Fixed information leak (bsc#1189166).
  • CVE-2021-38093: Fixed integer overflow vulnerability in filter_robert() (bsc#1190734)
  • CVE-2021-38092: Fixed integer overflow vulnerability in filter_prewitt() (bsc#1190733)
  • CVE-2021-38094: Fixed integer overflow vulnerability in filter_sobel() (bsc#1190735)
  • CVE-2020-22037: Fixed denial of service vulnerability caused by memory leak in avcodec_alloc_context3() (bsc#1186756)
  • CVE-2020-35965: Fixed out-of-bounds write in decode_frame() (bsc#1187852)
  • CVE-2020-20892: Fixed an issue with filter_frame() (bsc#1190719)
  • CVE-2020-20891: Fixed a buffer overflow vulnerability in config_input() (bsc#1190718)
  • CVE-2020-20895: Fixed a buffer overflow vulnerability in function filter_vertically_##name (bsc#1190722)
  • CVE-2020-20896: Fixed an issue with latm_write_packet() (bsc#1190723)
  • CVE-2020-20899: Fixed a buffer overflow vulnerability in config_props() (bsc#1190726)
  • CVE-2020-20902: Fixed an out-of-bounds read vulnerabilit long_term_filter() (bsc#1190729)
Record
openSUSE-SU-2021:3521-1
Updated
2026-11-02
OSVSUSE-SU-2021:3521-1 No score

Security update for ffmpeg

This update for ffmpeg fixes the following issues:

  • CVE-2021-3566: Fixed information leak (bsc#1189166).
  • CVE-2021-38093: Fixed integer overflow vulnerability in filter_robert() (bsc#1190734)
  • CVE-2021-38092: Fixed integer overflow vulnerability in filter_prewitt() (bsc#1190733)
  • CVE-2021-38094: Fixed integer overflow vulnerability in filter_sobel() (bsc#1190735)
  • CVE-2020-22037: Fixed denial of service vulnerability caused by memory leak in avcodec_alloc_context3() (bsc#1186756)
  • CVE-2020-35965: Fixed out-of-bounds write in decode_frame() (bsc#1187852)
  • CVE-2020-20892: Fixed an issue with filter_frame() (bsc#1190719)
  • CVE-2020-20891: Fixed a buffer overflow vulnerability in config_input() (bsc#1190718)
  • CVE-2020-20895: Fixed a buffer overflow vulnerability in function filter_vertically_##name (bsc#1190722)
  • CVE-2020-20896: Fixed an issue with latm_write_packet() (bsc#1190723)
  • CVE-2020-20899: Fixed a buffer overflow vulnerability in config_props() (bsc#1190726)
  • CVE-2020-20902: Fixed an out-of-bounds read vulnerabilit long_term_filter() (bsc#1190729)
Record
SUSE-SU-2021:3521-1
Updated
2026-11-02
OSVSUSE-SU-2023:0005-1 No score

Security update for ffmpeg

This update for ffmpeg fixes the following issues:

  • CVE-2022-3109: Fixed null pointer dereference in vp3_decode_frame() (bsc#1206442).
  • CVE-2020-22042: Fixed a denial of service vulnerability led by a memory leak in the link_filter_inouts function in libavfilter/graphparser.c. (bsc#1186761)
  • CVE-2021-38094: Fixed an integer overflow vulnerability in function filter_sobel in libavfilter/vf_convolution.c (bsc#1190735).
  • CVE-2021-38093: Fixed an integer Overflow vulnerability in function filter_robert in libavfilter/vf_convolution.c (bsc#1190734).
  • CVE-2021-38092: Fixed an Integer Overflow vulnerability in function filter_prewitt in libavfilter/vf_convolution.c (bsc#1190733).
  • CVE-2020-22037: Fixed a denial of service vulnerability due to a memory leak in avcodec_alloc_context3 at options.c (bsc#1186756).
  • CVE-2021-3566: Fixed an exposure of sensitive information on ffmpeg version prior to 4.3 (bsc#1189166).
  • CVE-2020-35965: Fixed an out-of-bounds write in decode_frame in libavcodec/exr.c (bsc#1187852).
  • CVE-2020-20892: Fixed a division by zero in function filter_frame in libavfilter/vf_lenscorrection.c (bsc#1190719).
  • CVE-2020-20891: Fixed a buffer overflow vulnerability in function config_input in libavfilter/vf_gblur.c (bsc#1190718).
  • CVE-2020-20895: Fixed a buffer overflow vulnerability in function filter_vertically_##name in libavfilter/vf_avgblur.c (bsc#1190722).
  • CVE-2020-20896: Fixed a NULL pointer dereference in function latm_write_packet in libavformat/latmenc.c (bsc#1190723).
  • CVE-2020-20899: Fixed a buffer overflow vulnerability in function config_props in libavfilter/vf_bwdif.c (bsc#1190726).
  • CVE-2020-20902: Fixed an out-of-bounds read vulnerability in long_term_filter function in g729postfilter.c (bsc#1190729).
Record
SUSE-SU-2023:0005-1
Updated
2026-11-02
OSVUSN-5167-1 No score

ffmpeg vulnerabilities

It was discovered that FFmpeg did not properly verify certain input when processing video and audio files. An attacker could possibly use this to send specially crafted input to the application, force a division by zero, and cause a denial of service (application crash). (CVE-2020-20445, CVE-2020-20446, CVE-2020-20453, CVE-2020-20892)

It was discovered that FFmpeg did not properly perform certain bit shift and memory operations. An attacker could possibly use this issue to expose sensitive information. (CVE-2020-20902)

It was discovered that FFmpeg did not properly perform memory management operations in various of its functions. An attacker could possibly use this issue to send specially crafted input to the application and cause a denial of service (application crash) or execute arbitrary code. (CVE-2020-21041, CVE-2020-20451, CVE-2020-21688, CVE-2020-21697, CVE-2020-22020, CVE-2020-22021, CVE-2020-22022, CVE-2020-22025, CVE-2020-22031, CVE-2020-22032, CVE-2020-22037, CVE-2020-22040, CVE-2020-22041, CVE-2020-22042, CVE-2020-22044)

It was discovered that FFmpeg did not properly perform memory management operations in various of its functions. An attacker could possibly use this issue to send specially crafted input to the application and cause a denial of service (application crash) or execute arbitrary code. (CVE-2020-22016, CVE-2020-22046, CVE-2020-22049, CVE-2020-22054)

It was discovered that FFmpeg did not properly perform memory management operations in various of its functions. An attacker could possibly use this issue to send specially crafted input to the application and cause a denial of service (application crash) or execute arbitrary code. (CVE-2020-35965)

It was discovered that FFmpeg did not properly handle data assigned to the tty demuxer. An attacker could possibly use this issue to send specially crafted input to the application and expose sensitive information. (CVE-2021-3566)

It was discovered that FFmpeg did not perform checks on function return values when encoding and formatting input video and audio files. An attacker could possibly use this issue to cause a denial of service (application crash) or execute arbitrary code. (CVE-2021-38114, CVE-2021-38171)

It was discovered that FFmpeg did not properly sanitize function returned data when calculating frame duration values. An attacker could possibly use this issue to cause an assertion failure and then cause a denial of service (application crash). (CVE-2021-38291)

Record
USN-5167-1
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
ffmpeg
Debian:12
 before 7:4.3-2
7:4.3-2
ffmpeg
Debian:13
 before 7:4.3-2
7:4.3-2
ffmpeg
Debian:14
 before 7:4.3-2
7:4.3-2
ffmpeg
Debian:9
From an advisory covering 15 CVEs
 before 7:3.2.15-0+deb9u3, plus listed versions
7:3.2.10-1~deb9u17:3.2.10-1~deb9u1~bpo8+17:3.2.11-1~deb9u17:3.2.12-1~deb9u17:3.2.14-1~deb9u1
Show 7 moreShow less
7:3.2.15-0+deb9u17:3.2.15-0+deb9u27:3.2.5-17:3.2.6-17:3.2.7-1~deb9u17:3.2.8-1~deb9u17:3.2.9-1~deb9u1
7:3.2.15-0+deb9u3
ffmpeg
Debian:10
From an advisory covering 6 CVEs
 before 7:4.1.9-0+deb10u1, plus listed versions
7:4.1.3-17:4.1.4-17:4.1.4-1~deb10u17:4.1.6-1~deb10u17:4.1.8-0+deb10u1
7:4.1.9-0+deb10u1
FFMPEG_jll
Julia
 before 4.3.1+0
4.3.1+0
ffmpeg
SUSE:Linux Enterprise Module for Desktop Applications 15 SP2
From an advisory covering 12 CVEs
 before 3.4.2-11.17.1
3.4.2-11.17.1
ffmpeg
SUSE:Linux Enterprise Module for Desktop Applications 15 SP3
From an advisory covering 12 CVEs
 before 3.4.2-11.17.1
3.4.2-11.17.1
ffmpeg
SUSE:Linux Enterprise Module for Package Hub 15 SP2
From an advisory covering 12 CVEs
 before 3.4.2-11.17.1
3.4.2-11.17.1
ffmpeg
SUSE:Linux Enterprise Module for Package Hub 15 SP3
From an advisory covering 12 CVEs
 before 3.4.2-11.17.1
3.4.2-11.17.1
Show 15 moreShow less
Affected packages
PackageAffectedFixed
ffmpeg
SUSE:Linux Enterprise Workstation Extension 15 SP2
From an advisory covering 12 CVEs
 before 3.4.2-11.17.1
3.4.2-11.17.1
ffmpeg
SUSE:Linux Enterprise Workstation Extension 15 SP3
From an advisory covering 12 CVEs
 before 3.4.2-11.17.1
3.4.2-11.17.1
ffmpeg
SUSE:Linux Enterprise High Performance Computing 15-ESPOS
From an advisory covering 14 CVEs
 before 3.4.2-150000.4.44.1
3.4.2-150000.4.44.1
ffmpeg
SUSE:Linux Enterprise High Performance Computing 15-LTSS
From an advisory covering 14 CVEs
 before 3.4.2-150000.4.44.1
3.4.2-150000.4.44.1
ffmpeg
SUSE:Linux Enterprise High Performance Computing 15 SP1-ESPOS
From an advisory covering 14 CVEs
 before 3.4.2-150000.4.44.1
3.4.2-150000.4.44.1
ffmpeg
SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSS
From an advisory covering 14 CVEs
 before 3.4.2-150000.4.44.1
3.4.2-150000.4.44.1
ffmpeg
SUSE:Linux Enterprise Server 15-LTSS
From an advisory covering 14 CVEs
 before 3.4.2-150000.4.44.1
3.4.2-150000.4.44.1
ffmpeg
SUSE:Linux Enterprise Server 15 SP1-BCL
From an advisory covering 14 CVEs
 before 3.4.2-150000.4.44.1
3.4.2-150000.4.44.1
ffmpeg
SUSE:Linux Enterprise Server 15 SP1-LTSS
From an advisory covering 14 CVEs
 before 3.4.2-150000.4.44.1
3.4.2-150000.4.44.1
ffmpeg
SUSE:Linux Enterprise Server for SAP Applications 15
From an advisory covering 14 CVEs
 before 3.4.2-150000.4.44.1
3.4.2-150000.4.44.1
ffmpeg
SUSE:Linux Enterprise Server for SAP Applications 15 SP1
From an advisory covering 14 CVEs
 before 3.4.2-150000.4.44.1
3.4.2-150000.4.44.1
ffmpeg
SUSE:Enterprise Storage 6
From an advisory covering 14 CVEs
 before 3.4.2-150000.4.44.1
3.4.2-150000.4.44.1
ffmpeg
Ubuntu:Pro:16.04:LTS
 before 7:2.8.17-0ubuntu0.1+esm4, plus listed versions
7:2.7.2-1build17:2.8.1-1ubuntu17:2.8.2-1ubuntu17:2.8.3-17:2.8.4-1
Show 16 moreShow less
7:2.8.4-1ubuntu17:2.8.4-1ubuntu27:2.8.4-1ubuntu37:2.8.4-1ubuntu47:2.8.6-1ubuntu17:2.8.6-1ubuntu27:2.8.8-0ubuntu0.16.04.17:2.8.10-0ubuntu0.16.04.17:2.8.11-0ubuntu0.16.04.17:2.8.14-0ubuntu0.16.04.17:2.8.15-0ubuntu0.16.04.17:2.8.15-0ubuntu0.16.04.1+esm17:2.8.17-0ubuntu0.17:2.8.17-0ubuntu0.1+esm17:2.8.17-0ubuntu0.1+esm27:2.8.17-0ubuntu0.1+esm3
7:2.8.17-0ubuntu0.1+esm4
ffmpeg
Ubuntu:Pro:16.04:LTS
From an advisory covering 29 CVEs
 before 7:2.8.17-0ubuntu0.1+esm4, plus listed versions
7:2.7.2-1build17:2.8.1-1ubuntu17:2.8.2-1ubuntu17:2.8.3-17:2.8.4-1
Show 16 moreShow less
7:2.8.4-1ubuntu17:2.8.4-1ubuntu27:2.8.4-1ubuntu37:2.8.4-1ubuntu47:2.8.6-1ubuntu17:2.8.6-1ubuntu27:2.8.8-0ubuntu0.16.04.17:2.8.10-0ubuntu0.16.04.17:2.8.11-0ubuntu0.16.04.17:2.8.14-0ubuntu0.16.04.17:2.8.15-0ubuntu0.16.04.17:2.8.15-0ubuntu0.16.04.1+esm17:2.8.17-0ubuntu0.17:2.8.17-0ubuntu0.1+esm17:2.8.17-0ubuntu0.1+esm27:2.8.17-0ubuntu0.1+esm3
7:2.8.17-0ubuntu0.1+esm4
ffmpeg
openSUSE:Leap 15.3
From an advisory covering 12 CVEs
 before 3.4.2-11.17.1
3.4.2-11.17.1

History

History
RecordedChangedSources
affected, facts
aliasesEUVD
first indexedCVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-3566 is a medium vulnerability (CVSS 5.5) in Ffmpeg, published August 5, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.88%, the 59th percentile. Fixed in ffmpeg 7:4.3-2.

References

Show 61 moreShow less
Pages All vulnerabilities Browse Docs Sources Guide Get API key
MoveEnter Open