CVE-2013-3675 in FFmpeg
Summary
by MITRE
The process_frame_obj function in sanm.c in libavcodec in FFmpeg before 1.2.1 does not validate width and height values, which allows remote attackers to cause a denial of service (integer overflow, out-of-bounds array access, and application crash) via crafted LucasArts Smush video data.
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Analysis
by VulDB Data Team • 05/14/2021
The vulnerability identified as CVE-2013-3675 resides within the FFmpeg multimedia framework's libavcodec library, specifically in the process_frame_obj function located in the sanm.c file. This flaw represents a classic case of insufficient input validation that can be exploited to execute remote denial of service attacks against systems processing LucasArts Smush video format files. The vulnerability affects FFmpeg versions prior to 1.2.1, making it a significant concern for any system that processes multimedia content using this library.
The technical root cause of this vulnerability stems from the absence of proper validation for width and height parameters within the process_frame_obj function. When processing crafted LucasArts Smush video data, the function fails to verify that the width and height values remain within acceptable bounds. This lack of validation creates a pathway for integer overflow conditions to occur, which subsequently leads to out-of-bounds array access patterns. The vulnerability manifests as a result of unchecked arithmetic operations that can produce values exceeding the maximum representable integers for the data types used, causing the application to access memory locations outside the intended array boundaries.
The operational impact of this vulnerability extends beyond simple denial of service, as it can potentially lead to application crashes and system instability. Remote attackers can exploit this weakness by crafting malicious LucasArts Smush video files that contain specially calculated width and height values designed to trigger the integer overflow condition. When such files are processed by vulnerable FFmpeg implementations, the application crashes due to the out-of-bounds memory access, effectively rendering the system unable to process legitimate multimedia content. This makes the vulnerability particularly dangerous in environments where automated multimedia processing occurs, such as content management systems, media servers, or web applications that accept user-uploaded video files.
This vulnerability aligns with CWE-190, which addresses integer overflow and underflow conditions, and demonstrates the critical importance of input validation in multimedia processing libraries. The attack pattern follows typical remote exploitation vectors described in the MITRE ATT&CK framework under the T1190 technique for exploitation of remote services. Organizations using FFmpeg for multimedia processing should prioritize patching this vulnerability, as it represents a straightforward path for attackers to disrupt services without requiring elevated privileges or specialized knowledge of the target system. The fix implemented in FFmpeg 1.2.1 involved adding proper validation checks for the width and height parameters to prevent the integer overflow conditions that led to the out-of-bounds memory access.
The broader implications of this vulnerability highlight the critical need for robust input validation in multimedia libraries that process complex file formats. Given the widespread use of FFmpeg across various applications, from media players to content delivery networks, the potential attack surface for this vulnerability extends far beyond simple denial of service scenarios. The vulnerability serves as a reminder that multimedia processing libraries must implement comprehensive validation mechanisms to prevent integer overflows and memory corruption issues that can be exploited by remote attackers. System administrators should ensure that all FFmpeg installations are updated to versions that include the relevant security patches, particularly in environments where untrusted multimedia content may be processed automatically.