#VU53601 Out-of-bounds write in FFmpeg - CVE-2020-35965

Vulnerability identifier: #VU53601

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-2020-35965

CWE-ID: CWE-787

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 vulnerable system.

The vulnerability exists due to a boundary error when processing untrusted input within the decode_frame() function in libavcodec/exr.c. A remote attacker can create a specially crafted file, trick the victim into opening it using the affected software, trigger out-of-bounds write and execute arbitrary code on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FFmpeg: 1.2 - 4.3.1

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External links
https://github.com/FFmpeg/FFmpeg/commit/3e5959b3457f7f1856d997261e6ac672bba49e8b
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=26532
https://github.com/FFmpeg/FFmpeg/commit/b0a8b40294ea212c1938348ff112ef1b9bf16bb3
https://lists.debian.org/debian-lts-announce/2021/01/msg00026.html
https://security.gentoo.org/glsa/202105-24

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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.