CVE-2013-0865 in FFmpeg
Summary
by MITRE
The vqa_decode_chunk function in libavcodec/vqavideo.c in FFmpeg before 1.0.4 and 1.1.x before 1.1.2 allows remote attackers to have an unspecified impact via a large (1) cbp0 or (2) cbpz chunk in Westwood Studios VQA Video file, which triggers an out-of-bounds write.
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Analysis
by VulDB Data Team • 05/04/2021
The vulnerability identified as CVE-2013-0865 represents a critical out-of-bounds write flaw within the FFmpeg multimedia framework's video decoding component. This vulnerability specifically affects the vqa_decode_chunk function located in libavcodec/vqavideo.c, which processes Westwood Studios VQA video files. The issue manifests when the decoder encounters malformed cbp0 or cbpz chunks with a value of one within VQA video streams, creating conditions that can lead to arbitrary code execution or system instability. The vulnerability exists in FFmpeg versions prior to 1.0.4 and 1.1.x versions prior to 1.1.2, making it a long-standing security concern that affected numerous applications relying on FFmpeg for video processing.
The technical exploitation of this vulnerability stems from insufficient input validation within the video decoding pipeline. When the vqa_decode_chunk function processes these malformed chunks, it fails to properly bounds-check array accesses or validate chunk parameters before using them as indices for memory operations. This allows an attacker to craft malicious VQA video files that, when processed by vulnerable FFmpeg implementations, cause the decoder to write data beyond the allocated memory boundaries. The out-of-bounds write can overwrite adjacent memory locations, potentially corrupting critical data structures, function pointers, or control flow information within the application. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and falls under the broader category of memory safety vulnerabilities that enable privilege escalation and remote code execution.
The operational impact of CVE-2013-0865 extends beyond simple playback functionality, as it can be exploited in various attack scenarios including web-based delivery, email attachments, or streaming media services. Any application that utilizes FFmpeg for video processing, including content management systems, media servers, video editing software, and web browsers with embedded media support, becomes potentially vulnerable to remote exploitation. The attack surface is particularly broad given FFmpeg's widespread adoption across both open-source and commercial multimedia applications. The vulnerability can be leveraged by attackers to execute arbitrary code with the privileges of the affected application, potentially leading to complete system compromise, data exfiltration, or denial of service conditions. This aligns with ATT&CK technique T1059, which covers command and scripting interpreter usage, and T1203, which involves exploitation for execution through various attack vectors.
Mitigation strategies for CVE-2013-0865 primarily focus on immediate software updates and input validation measures. Organizations should prioritize upgrading to FFmpeg versions 1.0.4 or later for the 1.0.x branch, and 1.1.2 or later for the 1.1.x branch where the vulnerability has been patched. Additionally, implementing strict input validation at application boundaries can provide defense-in-depth protection, particularly for systems that cannot immediately update their FFmpeg implementations. Network-based protections such as content filtering and sandboxing mechanisms can help prevent exploitation attempts by blocking suspicious VQA video files. Security monitoring should include detection of unusual memory access patterns and out-of-bounds write attempts in multimedia processing components. The vulnerability demonstrates the importance of comprehensive input validation and memory safety practices in multimedia frameworks, as highlighted by industry standards and best practices for secure coding. Regular security assessments and vulnerability scanning should be implemented to identify other potential buffer overflow conditions in multimedia processing libraries that may present similar security risks.