FFmpeg 4.0.1 libavcodec/vc1_block.c vc1_put_blocks_clamped mqaunt out-of-bounds

Summaryinfo

A vulnerability classified as critical has been found in FFmpeg 4.0.1. Affected is the function vc1_put_blocks_clamped of the file libavcodec/vc1_block.c. This manipulation of the argument mqaunt as part of Negative Value causes out-of-bounds. This vulnerability is tracked as CVE-2018-13305. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in FFmpeg 4.0.1 (Multimedia Processing Software). It has been declared as critical. Affected by this vulnerability is the function vc1_put_blocks_clamped of the file libavcodec/vc1_block.c. The manipulation of the argument mqaunt as part of a Negative Value leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In FFmpeg 4.0.1, due to a missing check for negative values of the mqaunt variable, the vc1_put_blocks_clamped function in libavcodec/vc1_block.c may trigger an out-of-array access while converting a crafted AVI file to MPEG4, leading to an information disclosure or a denial of service.

The bug was discovered 06/27/2018. The weakness was disclosed 07/05/2018 (Website). It is possible to read the advisory at github.com. This vulnerability is known as CVE-2018-13305 since 07/05/2018. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability was handled as a non-public zero-day exploit for at least 8 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 120152 (SUSE SLED15 / SLES15 Security Update : ffmpeg (SUSE-SU-2018:3609-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family SuSE Local Security Checks and running in the context l.

Upgrading eliminates this vulnerability. A possible mitigation has been published 5 months after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (120152). The entries VDB-120426, VDB-120425, VDB-120424 and VDB-120423 are pretty similar. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Multimedia Processing Software

Name

• FFmpeg

Version

• 4.0.1

License

• open-source

Website

• Product: https://ffmpeg.org/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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