CVE-2016-2326 in FFmpeg
Summary
by MITRE
Integer overflow in the asf_write_packet function in libavformat/asfenc.c in FFmpeg before 2.8.5 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted PTS (aka presentation timestamp) value in a .mov file.
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Analysis
by VulDB Data Team • 07/08/2022
The vulnerability CVE-2016-2326 represents a critical integer overflow flaw within the FFmpeg multimedia framework's ASF (Advanced Systems Format) encoder component. This issue specifically affects the asf_write_packet function located in libavformat/asfenc.c and impacts FFmpeg versions prior to 2.8.5. The vulnerability arises from insufficient input validation when processing presentation timestamp values within .mov files, creating a scenario where remote attackers can manipulate the encoding process through crafted timestamp data. The flaw falls under CWE-190, which categorizes integer overflow conditions that can lead to unpredictable behavior and system instability. This vulnerability demonstrates a classic example of how multimedia processing libraries can be exploited through malformed input data, particularly when dealing with timestamp handling during file encoding operations.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious .mov file containing an improperly formatted PTS value that triggers integer overflow during the encoding process. The asf_write_packet function fails to properly validate the range of presentation timestamp values, allowing a crafted timestamp to exceed the maximum representable value for the integer data type used in the encoding calculations. This overflow condition can cause the encoder to allocate insufficient memory buffers or trigger unexpected behavior in the packet writing mechanism. The vulnerability is particularly concerning because it can be triggered remotely through file processing operations, making it exploitable in automated systems that handle multimedia file uploads or processing. The integer overflow manifests as a denial of service condition where the application crashes or becomes unresponsive, though the potential for more severe impacts including arbitrary code execution cannot be ruled out based on the unspecified nature of the vulnerability's effects.
The operational impact of CVE-2016-2326 extends beyond simple service disruption to potentially compromise entire multimedia processing pipelines and content delivery systems. Organizations relying on FFmpeg for video transcoding, streaming, or file conversion services face significant risk when handling untrusted .mov files, as the vulnerability can be exploited to crash processing servers or cause system instability. This vulnerability particularly affects content management systems, video streaming platforms, and automated media processing workflows that automatically encode user-uploaded files. The attack surface is broad given that .mov files are widely used across various multimedia applications and platforms, making the exploitation vector particularly dangerous in environments where user-generated content is processed. The vulnerability's potential for unspecified other impacts suggests that under certain conditions, attackers might be able to achieve more sophisticated exploitation techniques, including memory corruption that could lead to code execution. This makes the vulnerability particularly concerning for security-conscious organizations that handle sensitive multimedia content or operate in regulated environments.
Mitigation strategies for CVE-2016-2326 focus primarily on upgrading to patched versions of FFmpeg, specifically FFmpeg 2.8.5 or later, which contain the necessary fixes for the integer overflow condition. System administrators should implement immediate patch management protocols to ensure all FFmpeg installations are updated, particularly in environments processing untrusted multimedia files. Additional protective measures include implementing strict input validation for multimedia file formats, employing sandboxed processing environments for file handling, and deploying network-based intrusion detection systems that can identify suspicious file processing patterns. The vulnerability highlights the importance of input validation in multimedia processing libraries and reinforces the need for comprehensive security testing of encoding components. Organizations should also consider implementing file type filtering mechanisms and automated malware scanning for user-uploaded multimedia content to reduce the risk of exploitation. From an ATT&CK framework perspective, this vulnerability maps to the T1059.007 technique for execution through multimedia processing and represents a critical weakness in the software supply chain that could be leveraged for broader system compromise. Regular security audits of multimedia processing pipelines and adherence to secure coding practices for integer handling in multimedia frameworks are essential defensive measures against similar vulnerabilities.