CVE-2021-3566
5.5 · MEDIUMOverview
CVE-2021-3566 is a medium-severity vulnerability affecting ffmpeg ffmpeg. It was published on August 5, 2021 and has a CVSS 3.1 base score of 5.5 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
Technical 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).
Remediation
Check the references section for vendor advisories and patches from ffmpeg. Update ffmpeg to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| ffmpeg | ffmpeg | >= 0, < 4.3 | Affected |
References
Frequently Asked Questions
What is CVE-2021-3566?
CVE-2021-3566 is a medium-severity vulnerability affecting ffmpeg ffmpeg. It was published on August 5, 2021 and has a CVSS 3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2021-3566?
This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-3566?
Check the references section for vendor advisories and patches from ffmpeg. Update ffmpeg to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-3566?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-3566 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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