#VU84800 Improper validation of array index in FFmpeg - CVE-2021-33815

Vulnerability identifier: #VU84800

Vulnerability risk: High

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-33815

CWE-ID: CWE-129

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
FFmpeg
Universal components / Libraries / Libraries used by multiple products

Vendor: ffmpeg.sourceforge.net

Description

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to an out-of-bounds array access within the dwa_uncompress() function in libavcodec/exr.c. A remote attacker can trick the victim to open a specially crafted image, trigger memory corruption and execute arbitrary code on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FFmpeg: 4.0 - 4.4.4

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External links
https://github.com/FFmpeg/FFmpeg/commit/26d3c81bc5ef2f8c3f09d45eaeacfb4b1139a777
https://security.gentoo.org/glsa/202312-14

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.