Input validation error in ffmpeg (Alpine package)

1) Input validation error

EUVDB-ID: #VU18320

Risk: Low

CVSSv3.1: 3 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-9718

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input within the subtitle decoder in ff_htmlmarkup_to_ass() function in libavcodec/htmlsubtitles.c when processing video files in Matroska format. A remote attacker can create a specially crafted video file, pass it to the affected application and consume all available CPU resources.

Mitigation

Install update from vendor's website.

Vulnerable software versions

ffmpeg (Alpine package): 3.4.4-r1

External links

http://git.alpinelinux.org/aports/commit/?id=8b2616ec00d3b29a5bdc2fce68c0594898b57b63
http://git.alpinelinux.org/aports/commit/?id=adac785d84798e462af5871aa7df312c6510c248
http://git.alpinelinux.org/aports/commit/?id=d8d38dabc6e30c901eb6bd6627d8337849d7c041
http://git.alpinelinux.org/aports/commit/?id=cf78a820406ae4481e937bc2fba252ff79c89a09
http://git.alpinelinux.org/aports/commit/?id=859fd99d06049c009c8b745626511cd681061a99

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.