CVE-2011-3504 in FFmpeg
Summary
by MITRE
The Matroska format decoder in FFmpeg before 0.8.3 does not properly allocate memory, which allows remote attackers to execute arbitrary code via a crafted file.
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Analysis
by VulDB Data Team • 11/20/2021
The vulnerability identified as CVE-2011-3504 represents a critical memory allocation flaw within the Matroska format decoder component of FFmpeg software version 0.8.2 and earlier. This issue falls under the category of memory corruption vulnerabilities and specifically manifests as an improper memory allocation mechanism that fails to adequately validate input data structures. The flaw exists in the handling of Matroska container format files which are widely used for multimedia content storage and transmission across various digital platforms. The vulnerability is particularly concerning because it enables remote code execution when a maliciously crafted Matroska file is processed by an affected FFmpeg instance, making it a prime target for exploitation in various attack scenarios.
The technical root cause of this vulnerability stems from inadequate bounds checking and memory management within the decoder's parsing logic. When FFmpeg processes a Matroska file, it allocates memory buffers based on parameters extracted from the file headers and metadata sections. However, the decoder fails to properly validate these parameters, allowing attackers to craft files with malformed or excessively large size indicators that cause the memory allocation routines to allocate insufficient memory or trigger buffer overflows. This improper handling of memory allocation creates opportunities for attackers to manipulate the program's execution flow through carefully constructed input data that can overwrite critical memory regions or execute arbitrary code within the context of the running application. The vulnerability is classified as a CWE-122 - Heap-based Buffer Overflow according to the Common Weakness Enumeration catalog, which specifically addresses heap memory corruption issues.
The operational impact of CVE-2011-3504 extends across numerous digital media processing environments where FFmpeg serves as a foundational component for multimedia handling. This includes content delivery networks, video streaming platforms, media processing servers, and digital asset management systems that rely on FFmpeg for format conversion and playback functionality. Attackers can exploit this vulnerability by delivering maliciously crafted Matroska files through various vectors including email attachments, web downloads, or file sharing platforms, potentially compromising systems that process such media content automatically. The remote execution capability means that even automated media processing systems can be targeted without requiring user interaction, making this vulnerability particularly dangerous in enterprise environments where media files are processed in bulk. According to ATT&CK framework, this vulnerability maps to T1203 - Exploitation for Client Execution and T1059 - Command and Scripting Interpreter, as it enables attackers to execute arbitrary code remotely through media processing workflows.
Mitigation strategies for CVE-2011-3504 primarily focus on immediate software updates and deployment of patched FFmpeg versions. Organizations should prioritize upgrading to FFmpeg version 0.8.3 or later where the memory allocation issues have been resolved through proper bounds checking and validation mechanisms. Additionally, implementing network-based controls such as content filtering and file type validation can help prevent the delivery of malicious Matroska files to vulnerable systems. System administrators should also consider implementing sandboxing mechanisms for media processing tasks and employing automated scanning solutions that can detect and quarantine suspicious media files before they are processed by FFmpeg components. The vulnerability highlights the importance of proper input validation and memory management practices in multimedia processing libraries, serving as a reminder of the critical security considerations required when handling complex binary formats that require extensive parsing and memory allocation operations.