NULL pointer dereference in Libav

1) NULL pointer dereference

EUVDB-ID: #VU37710

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-1000460

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

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

In line libavcodec/h264dec.c:500 in libav(v13_dev0), ffmpeg(n3.4), chromium(56 prior Feb 13, 2017), the return value of init_get_bits is ignored and get_ue_golomb(&gb) is called on an uninitialized get_bits context, which causes a NULL deref exception.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Libav: 13_dev0

FFmpeg: 3.4 - 13_dev0

CPE2.3

• cpe:2.3:a:libav:libav:13_dev0:*:*:*:*:*:*:*
• cpe:2.3:a:ffmpeg_sourceforge_net:ffmpeg:13_dev0:*:*:*:*:*:*:*
• cpe:2.3:a:ffmpeg_sourceforge_net:ffmpeg:3.4:*:*:*:*:*:*:*

External links

http://bugzilla.libav.org/show_bug.cgi?id=952
http://chromium.googlesource.com/chromium/third_party/ffmpeg/+/8e313ca08800178efce00045e07dc494d437b70c
http://lists.debian.org/debian-lts-announce/2019/03/msg00041.html
http://lists.ffmpeg.org/pipermail/ffmpeg-cvslog/2017-January/104221.html

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.