CVE-2012-0852 in libav
Summary
by MITRE
The adpcm_decode_frame function in adpcm.c in libavcodec in FFmpeg before 0.9.1 and in Libav 0.5.x before 0.5.9, 0.6.x before 0.6.6, 0.7.x before 0.7.6, and 0.8.x before 0.8.3 allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via an ADPCM file with the number of channels not equal to two.
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Analysis
by VulDB Data Team • 12/08/2021
The vulnerability identified as CVE-2012-0852 represents a critical security flaw in the FFmpeg multimedia framework's audio decoding capabilities. This issue affects the adpcm_decode_frame function within the libavcodec library, which processes ADPCM (Adaptive Differential Pulse Code Modulation) audio files. The vulnerability specifically targets versions of FFmpeg prior to 0.9.1 and various Libav versions before their respective patches, creating a significant risk for systems that process multimedia content from untrusted sources. The flaw manifests when an ADPCM file contains a channel count that deviates from the expected two-channel configuration, leading to unpredictable behavior in the audio decoding process.
The technical implementation of this vulnerability stems from inadequate input validation within the ADPCM decoding routine. When the adpcm_decode_frame function encounters an ADPCM file with a channel count other than two, it fails to properly handle the unexpected parameter, resulting in memory access violations and potential code execution. This type of flaw falls under CWE-129, which encompasses issues related to insufficient validation of length parameters, and represents a classic case of buffer over-read or under-read conditions that can lead to system instability. The function does not perform proper bounds checking on the channel count parameter, allowing maliciously crafted ADPCM files to trigger memory corruption during the decoding process.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enable remote code execution, making it particularly dangerous for applications that automatically process multimedia content. Attackers can craft specially formatted ADPCM files that, when processed by vulnerable systems, cause the application to crash or potentially execute arbitrary code with the privileges of the affected process. This risk is amplified in server environments where multimedia processing occurs automatically, such as content management systems, media servers, or any application that accepts user-uploaded audio files. The vulnerability can be exploited through various attack vectors including web applications, email attachments, or file sharing systems that process ADPCM audio data without proper sanitization.
Systems affected by CVE-2012-0852 include not only the core FFmpeg library but also any software that relies on Libav libraries, particularly those implementing audio processing capabilities. This vulnerability is categorized under the ATT&CK technique T1203, which involves exploitation of software vulnerabilities for privilege escalation or code execution. Organizations using affected versions should prioritize immediate patching, as the vulnerability exists in widely deployed multimedia frameworks and is likely to be targeted by automated exploitation tools. The patching process requires updating to FFmpeg version 0.9.1 or later, or to the corresponding patched versions of Libav, which include proper validation of channel count parameters in the ADPCM decoding process. Security monitoring should focus on detecting unusual audio file processing patterns and potential attempts to exploit this vulnerability through crafted media files.