#VU29635 Use-after-free in FFmpeg - CVE-2020-13904

Vulnerability identifier: #VU29635

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-2020-13904

CWE-ID: CWE-416

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 use-after-free error in FFmpeg when processing a crafted EXTINF duration in an m3u8 file because parse_playlist in libavformat/hls.c frees a pointer, and later that pointer is accessed in av_probe_input_format3 in libavformat/format.c. A remote attacker can trick the victim to open a specially crafted media file or playlist, trigger a use-after-free error and execute arbitrary code on the target system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FFmpeg: 2.0 - 4.2.3

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External links
https://patchwork.ffmpeg.org/project/ffmpeg/patch/20200529033905.41926-1-lq@chinaffmpeg.org/
https://trac.ffmpeg.org/ticket/8673
https://www.debian.org/security/2020/dsa-4722

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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.