CVE-2011-3929 in FFmpeg
Summary
by MITRE
The avpriv_dv_produce_packet function in libavcodec in FFmpeg 0.7.x before 0.7.12 and 0.8.x before 0.8.11 and in Libav 0.5.x before 0.5.9, 0.6.x before 0.6.6, 0.7.x before 0.7.5, and 0.8.x before 0.8.1 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) and possibly execute arbitrary code via a crafted DV file.
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Analysis
by VulDB Data Team • 12/08/2021
The vulnerability identified as CVE-2011-3929 represents a critical security flaw affecting multimedia processing libraries used extensively across various operating systems and applications. This vulnerability resides within the avpriv_dv_produce_packet function of FFmpeg and its fork Libav, which are fundamental components in video and audio processing for numerous software applications. The flaw manifests when these libraries process specially crafted DV (Digital Video) files, creating a condition that can lead to system instability and potential code execution. The affected versions span multiple releases including FFmpeg 0.7.x before 0.7.12 and 0.8.x before 0.8.11, alongside various Libav versions, indicating a widespread impact across the multimedia processing ecosystem.
The technical nature of this vulnerability stems from improper input validation within the DV file processing pipeline. When a maliciously crafted DV file is processed by the affected libraries, the avpriv_dv_produce_packet function fails to properly handle edge cases in the file structure, leading to a NULL pointer dereference condition. This type of flaw is categorized under CWE-476 as NULL pointer dereference, which occurs when software attempts to access memory through a pointer that has not been properly initialized or has been set to NULL. The vulnerability's exploitation path involves feeding the multimedia library a specially constructed DV file that contains malformed data structures, causing the processing function to attempt operations on uninitialized or invalid memory pointers. This fundamental breakdown in input validation creates a scenario where the application crashes during processing or potentially allows for arbitrary code execution through controlled memory manipulation.
The operational impact of this vulnerability extends far beyond simple denial of service conditions, presenting significant risks to system security and availability. Attackers can leverage this flaw to disrupt services by causing application crashes, which may result in complete system instability when the affected libraries are used in critical applications such as media servers, content management systems, or video processing pipelines. The potential for arbitrary code execution adds an additional layer of risk, as malicious actors could potentially gain unauthorized control over systems processing multimedia content. This vulnerability particularly affects environments where automated media processing occurs, such as web applications that accept user-uploaded videos, content delivery networks, or media processing services. The widespread adoption of FFmpeg and Libav across different platforms means that systems utilizing these libraries for video processing are vulnerable, creating a substantial attack surface that could be exploited by threat actors seeking to compromise system integrity or availability.
Mitigation strategies for CVE-2011-3929 primarily focus on immediate software updates and patches to address the underlying vulnerability in the affected libraries. System administrators should prioritize updating all installations of FFmpeg and Libav to versions that contain the fix, specifically FFmpeg 0.7.12 and 0.8.11 or later, and corresponding Libav versions. The remediation process should include comprehensive testing of updated libraries in staging environments to ensure compatibility with existing applications before deployment in production systems. Additional protective measures include implementing input validation and sanitization for all multimedia file processing, particularly when handling user-uploaded content, which aligns with ATT&CK technique T1059.007 for input validation and T1203 for exploitation of remote services. Organizations should also consider implementing network segmentation and access controls to limit exposure of systems running vulnerable multimedia processing libraries. The vulnerability's classification under CWE-476 and its potential for code execution make it particularly important to maintain up-to-date security patches and implement proper application sandboxing techniques to contain potential exploitation attempts.