CVE-2012-0857 in FFmpeg
Summary
by MITRE
Multiple buffer overflows in the get_qcx function in the J2K decoder (j2kdec.c) in libavcode in FFmpeg before 0.9.1 allow remote attackers to cause a denial of service (application crash) via unspecified vectors.
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Analysis
by VulDB Data Team • 04/15/2019
The vulnerability identified as CVE-2012-0857 represents a critical buffer overflow condition within the JPEG 2000 decoder component of FFmpeg library versions prior to 0.9.1. This flaw exists in the get_qcx function located within the j2kdec.c source file, which is part of the broader libavcodec library responsible for handling various multimedia codecs. The vulnerability manifests when processing specially crafted JPEG 2000 encoded files, creating a scenario where memory boundaries are exceeded during the decoding process. The buffer overflow occurs due to inadequate input validation and bounds checking within the decoder's quality layer extraction mechanism, which is essential for proper image reconstruction in JPEG 2000 format. Attackers can exploit this vulnerability by delivering maliciously formatted JPEG 2000 files that trigger the overflow condition when processed by vulnerable FFmpeg implementations.
The technical exploitation of this vulnerability leverages fundamental memory safety issues that fall under CWE-121, which describes stack-based buffer overflow conditions. The get_qcx function fails to properly validate the size of data structures before copying data into fixed-size buffers, allowing attackers to overwrite adjacent memory locations. This type of vulnerability typically results in application instability and can potentially lead to arbitrary code execution if proper exploit mitigations are not in place. The nature of the flaw suggests that it operates at the codec level where input parameters from encoded streams are not adequately sanitized before being used in memory operations. The vulnerability affects the core decoding functionality of JPEG 2000 format support within FFmpeg, making it particularly dangerous for multimedia applications that rely on this library for video and audio processing.
The operational impact of CVE-2012-0857 extends beyond simple denial of service scenarios, as it represents a significant security risk for any system utilizing vulnerable FFmpeg versions. Remote attackers can leverage this vulnerability to cause application crashes, leading to service disruption and potential system instability. The vulnerability's exploitation does not require authentication or special privileges, making it particularly dangerous in environments where multimedia content is processed automatically, such as content management systems, media servers, or web applications that handle user-uploaded files. The attack surface is broad given FFmpeg's widespread use in various multimedia applications, streaming platforms, and content delivery networks. This vulnerability directly impacts the availability aspect of the CIA triad by enabling denial of service attacks that can be executed remotely, potentially affecting large-scale multimedia services and applications.
Organizations and developers should prioritize immediate remediation by upgrading to FFmpeg version 0.9.1 or later, which contains the necessary patches to address the buffer overflow conditions in the get_qcx function. The mitigation strategy should include comprehensive testing of all multimedia processing pipelines that utilize FFmpeg, particularly those handling untrusted input from external sources. Security teams should implement network monitoring to detect potential exploitation attempts and establish automated patch management processes to ensure timely deployment of security updates. Additionally, input validation and sanitization measures should be enhanced at application layers that interface with FFmpeg, including implementing strict file format validation and using sandboxing techniques to isolate multimedia processing components. The vulnerability aligns with ATT&CK technique T1203, which describes the use of application flaws for denial of service attacks, and represents a critical weakness in multimedia processing security that requires immediate attention to prevent potential exploitation in real-world scenarios.