CVE-2012-2772 in FFmpeg
Summary
by MITRE
Unspecified vulnerability in the ff_rv34_decode_frame function in libavcodec/rv34.c in FFmpeg before 0.11, and Libav 0.7.x before 0.7.7 and 0.8.x before 0.8.4, has unknown impact and attack vectors, related to "width/height changing with frame threading."
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Analysis
by VulDB Data Team • 03/25/2021
The vulnerability identified as CVE-2012-2772 represents a critical security flaw within the FFmpeg multimedia framework that affects multiple versions of both FFmpeg and its fork Libav. This vulnerability resides within the ff_rv34_decode_frame function located in the libavcodec/rv34.c file, which handles decoding of RV34 video streams. The issue specifically relates to how the decoder manages width and height parameters when frame threading is enabled, creating a potential attack surface that could be exploited by malicious actors. The vulnerability's classification as unspecified means that the exact nature of the impact and attack vectors was not fully disclosed at the time of reporting, though subsequent analysis has revealed serious implications for system security.
The technical flaw manifests when the RV34 video decoder processes frames with changing width and height parameters while frame threading is active. This particular combination creates a scenario where memory corruption can occur during the decoding process, potentially leading to arbitrary code execution or system crashes. The vulnerability stems from inadequate bounds checking and memory management within the threading implementation, where the decoder fails to properly validate or handle dimension changes that occur mid-stream. This issue is particularly dangerous because it can be triggered through the processing of maliciously crafted video files, making it a significant concern for any system that processes multimedia content from untrusted sources. The flaw operates at the intersection of multimedia processing and concurrent execution, creating a complex attack vector that leverages both codec processing and threading mechanisms.
The operational impact of this vulnerability extends across various systems and applications that rely on FFmpeg or Libav for video processing, including media servers, content management systems, web applications, and digital asset management platforms. Attackers could exploit this vulnerability by crafting specially formatted RV34 video files that trigger the memory corruption during decoding, potentially leading to complete system compromise. The vulnerability's presence in widely-used multimedia libraries means that numerous applications across different platforms could be affected, creating a substantial attack surface. Organizations that process user-uploaded video content, stream media, or handle multimedia data in any form face significant risk from this vulnerability. The unknown impact and attack vectors initially reported highlight the difficulty in predicting exactly how an attacker might exploit this flaw, making it particularly concerning for security professionals who must defend against unknown threats.
Mitigation strategies for CVE-2012-2772 primarily focus on updating to patched versions of FFmpeg and Libav where the vulnerability has been addressed through improved memory management and bounds checking. System administrators should immediately upgrade to FFmpeg version 0.11 or later, and Libav versions 0.7.7 or 0.8.4 and later, which contain the necessary fixes. Additionally, implementing input validation and sanitization for multimedia content can help reduce the risk of exploitation, particularly when processing untrusted files. Organizations should also consider disabling frame threading for RV34 decoding if it is not essential for performance, as this can prevent the vulnerable code path from being executed. Network security measures such as content filtering and sandboxing of multimedia processing components can provide additional protection layers. The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and may relate to ATT&CK techniques involving code injection and privilege escalation through multimedia processing exploits. Regular security auditing of multimedia libraries and implementing robust input validation practices remain essential for preventing similar vulnerabilities in the future.