CVE-2014-9604 in FFmpeg
Summary
by MITRE
libavcodec/utvideodec.c in FFmpeg before 2.5.2 does not check for a zero value of a slice height, which allows remote attackers to cause a denial of service (out-of-bounds array access) or possibly have unspecified other impact via crafted Ut Video data, related to the (1) restore_median and (2) restore_median_il functions.
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Analysis
by VulDB Data Team • 03/08/2022
The vulnerability identified as CVE-2014-9604 resides within the FFmpeg multimedia framework, specifically in the utvideodec.c file that handles Ut Video decoding operations. This flaw represents a classic buffer over-read condition that occurs when the software fails to validate input parameters before processing them. The vulnerability is particularly concerning because it affects a widely used multimedia processing library that powers numerous applications and systems across different platforms. The issue manifests when the slice height parameter is set to zero, creating a scenario where subsequent array access operations attempt to reference memory locations outside the allocated bounds. This type of vulnerability falls under the category of improper input validation as defined by CWE-248, where an application fails to properly check input values before using them in operations that could lead to memory corruption.
The technical implementation of this vulnerability involves two specific functions within the Ut Video decoder: restore_median and restore_median_il. These functions are responsible for restoring median values during the video decoding process and operate on arrays of data that are dimensioned based on slice height parameters. When a zero value is passed for slice height, the mathematical calculations used to determine array indices become invalid, leading to out-of-bounds memory access patterns. The absence of proper validation means that attackers can craft malicious Ut Video files with zero slice height values, causing the decoder to attempt accessing memory locations that may not be allocated or accessible to the process. This vulnerability demonstrates the classic characteristics of a denial of service attack through memory corruption, but the unspecified other impacts suggest potential for more serious consequences including code execution or information disclosure depending on the execution context.
The operational impact of CVE-2014-9604 extends beyond simple denial of service scenarios, as it affects systems that process or transmit multimedia content through FFmpeg-based applications. Any application or service that accepts Ut Video encoded content without proper input validation becomes vulnerable to this attack, including media servers, streaming platforms, content management systems, and multimedia processing pipelines. The remote nature of the attack means that a malicious actor could exploit this vulnerability from anywhere on the network, making it particularly dangerous in environments where users can upload or submit media files. Attackers could leverage this vulnerability to disrupt services by causing crashes or to potentially escalate the attack to achieve more severe outcomes such as arbitrary code execution, especially if the affected system has additional vulnerabilities or if the attacker can control the execution environment. This vulnerability aligns with ATT&CK technique T1203, which covers exploitation of remote services through input validation flaws, and represents a common vector for service disruption attacks in multimedia processing systems.
Mitigation strategies for CVE-2014-9604 should focus on immediate patching of FFmpeg installations to version 2.5.2 or later, where the validation checks for slice height parameters have been implemented. Organizations should also consider implementing input validation at the application layer, where possible, to add an additional defense-in-depth measure. Network-based solutions such as content filtering and media validation systems can help prevent malicious Ut Video files from reaching vulnerable systems. Additionally, system administrators should monitor for unusual processing behavior or crashes in multimedia processing services, as these could indicate exploitation attempts. The vulnerability highlights the importance of thorough input validation in multimedia processing libraries and serves as a reminder of the critical need for proper bounds checking in array operations, particularly in security-sensitive applications that process untrusted input data. Regular security assessments and updates of multimedia frameworks should be part of standard operational procedures to prevent similar vulnerabilities from being exploited in the future.