CVE-2012-2790 in FFmpeg
Summary
by MITRE
Unspecified vulnerability in the read_var_block_data function in libavcodec/alsdec.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 the "number of decoded samples in first sub-block in BGMC mode."
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Analysis
by VulDB Data Team • 12/13/2021
The vulnerability identified as CVE-2012-2790 represents a critical security flaw affecting multimedia processing libraries within the FFmpeg and Libav ecosystems. This issue resides in the read_var_block_data function located in libavcodec/alsdec.c, which handles audio decoding operations for the Advanced Lossless Audio Codec. The vulnerability specifically targets the "number of decoded samples in first sub-block in BGMC mode" parameter, indicating a potential buffer manipulation or arithmetic overflow condition that could be exploited through malformed audio files. The affected versions include FFmpeg prior to 0.11 and Libav versions before 0.7.7 and 0.8.4, highlighting the widespread nature of this vulnerability across multiple media processing implementations.
The technical nature of this vulnerability stems from insufficient input validation within the audio decoding pipeline, where the read_var_block_data function fails to properly sanitize or bounds-check the sample count parameter during BGMC (Background and Foreground Model Coding) mode processing. This weakness creates potential for arbitrary code execution or denial of service conditions when processing specially crafted audio files. The vulnerability operates at the codec level, meaning that any application relying on FFmpeg or Libav for audio decoding could be susceptible to exploitation. The unspecified impact and attack vectors suggest that this flaw could potentially allow attackers to execute malicious code on systems processing affected media files, with the potential for remote code execution depending on the specific implementation and usage context.
From an operational standpoint, this vulnerability presents significant risk to organizations deploying multimedia applications that utilize FFmpeg or Libav libraries for audio processing. The attack surface extends to any system that processes audio content through these libraries, including media servers, content delivery networks, streaming platforms, and multimedia applications. The vulnerability's classification as a buffer-related issue aligns with CWE-129, which addresses insufficient validation of length of input buffers, and potentially CWE-190, concerning integer overflow or wraparound conditions. Security teams should prioritize patching affected systems and implementing network segmentation to prevent exploitation of this vulnerability in production environments.
Mitigation strategies for CVE-2012-2790 should focus on immediate patch deployment for all affected FFmpeg and Libav installations, with particular attention to systems processing untrusted audio content. Organizations should implement input validation controls at network boundaries and consider deploying intrusion detection systems to monitor for exploitation attempts. The ATT&CK framework's T1203 technique, which covers "Exploitation for Client Execution," could be relevant for threat detection, as this vulnerability could enable attackers to execute arbitrary code on vulnerable systems. Additionally, security professionals should conduct comprehensive vulnerability assessments across all multimedia processing systems and ensure that automated patch management processes are in place to maintain protection against similar future vulnerabilities. The remediation approach should also include monitoring for any reported exploitation attempts and maintaining updated threat intelligence feeds to detect potential variant attacks targeting similar codec vulnerabilities.