CVE-2012-2794 in FFmpeg
Summary
by MITRE
Unspecified vulnerability in the decode_mb_info function in libavcodec/indeo5.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 in which the "allocated tile size ... mismatches parameters."
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Analysis
by VulDB Data Team • 12/13/2021
The vulnerability identified as CVE-2012-2794 resides within the FFmpeg multimedia framework's video decoding component, specifically in the decode_mb_info function located in libavcodec/indeo5.c. This issue affects multiple versions of both FFmpeg and its fork Libav, creating a significant security concern for systems processing video content. The flaw manifests when the allocated tile size in the video decoding process does not align properly with the expected parameters, creating a condition that could potentially be exploited by malicious actors. The vulnerability's classification as unspecified means that the exact nature of the impact and attack vectors remained unclear at the time of initial reporting, though the underlying technical issue was well-defined within the codebase.
The technical implementation of this vulnerability stems from improper memory management and parameter validation within the video decoding pipeline. The decode_mb_info function processes macroblock information for Indeo 5 video format decoding, where the tile size allocation mechanism fails to properly validate the relationship between allocated memory space and the expected video parameters. This mismatch creates potential for memory corruption scenarios that could be leveraged to execute arbitrary code or cause application crashes. The issue represents a classic buffer over-read or memory corruption vulnerability where the system's handling of video frame parameters does not adequately protect against malformed input data. According to CWE classification, this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and potentially CWE-787, concerning out-of-bounds write operations. The vulnerability operates at the intersection of software security and multimedia processing, where the complexity of video decoding algorithms creates numerous potential attack surfaces.
The operational impact of CVE-2012-2794 extends beyond simple application instability, as it represents a potential remote code execution vector that could be exploited by attackers. Systems utilizing FFmpeg or Libav for video processing, particularly those handling untrusted video content from web applications, media servers, or file sharing platforms, face significant risk. The vulnerability could be triggered through specially crafted video files that exploit the tile size parameter mismatch during decoding, potentially allowing attackers to execute malicious code with the privileges of the affected application. This poses particular concern for web applications, content delivery networks, and media processing servers that automatically decode video content without proper input validation. The attack surface is broad given FFmpeg's widespread adoption across various platforms and applications, including browsers, media players, and server-side video processing systems. According to ATT&CK framework categorization, this vulnerability would fall under T1203, which covers exploitation for privilege escalation, and potentially T1059 for command and scripting interface usage if exploitation is successful.
Mitigation strategies for CVE-2012-2794 require immediate patching of affected software versions, as the vulnerability exists in multiple versions of both FFmpeg and Libav. Organizations should prioritize updating to FFmpeg 0.11 or later, and Libav versions 0.7.7 and 0.8.4 or later, which contain the necessary fixes for the tile size parameter validation. Additionally, implementing input validation measures that sanitize video content before processing can provide defense-in-depth protection. System administrators should consider deploying network-based intrusion detection systems that can identify potentially malicious video content patterns, while also implementing proper access controls to limit exposure of affected systems. The vulnerability highlights the importance of maintaining up-to-date multimedia libraries and implementing robust security practices in media processing environments. Organizations should also conduct regular vulnerability assessments of their multimedia processing pipelines and implement automated patch management systems to ensure timely remediation of similar security issues.