CVE-2011-4364 in libav
Summary
by MITRE
Buffer overflow in the Sierra VMD decoder in libavcodec in FFmpeg 0.5.x before 0.5.7, 0.6.x before 0.6.4, 0.7.x before 0.7.9 and 0.8.x before 0.8.8; and in Libav 0.5.x before 0.5.6, 0.6.x before 0.6.4, and 0.7.x before 0.7.3 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted VMD file, related to corrupted streams.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 12/12/2021
The vulnerability identified as CVE-2011-4364 represents a critical buffer overflow flaw within the Sierra VMD decoder component of FFmpeg and Libav multimedia frameworks. This vulnerability affects multiple versions of these widely-used open-source libraries that handle audio and video processing across numerous applications and operating systems. The flaw specifically manifests in the handling of Sierra VMD (Video Movie) file format decoding, which is commonly used in older video games and multimedia applications. The buffer overflow occurs when processing malformed or crafted VMD files that contain corrupted stream data, creating a condition where attacker-controlled input can overwrite adjacent memory locations beyond the allocated buffer boundaries.
The technical implementation of this vulnerability stems from inadequate input validation and bounds checking within the VMD decoder's parsing logic. When the decoder encounters a malformed VMD file with corrupted stream data, it fails to properly validate the size and structure of the incoming data before attempting to copy it into fixed-size buffers. This lack of proper boundary checking creates an exploitable condition where an attacker can craft a specially designed VMD file that, when processed by an affected library, triggers memory corruption. The vulnerability is particularly concerning because it can be triggered through normal media playback operations, making it accessible to remote attackers who can deliver malicious VMD files via web browsers, email attachments, or other media delivery mechanisms.
The operational impact of CVE-2011-4364 extends beyond simple denial of service conditions to potentially enable remote code execution. While the primary effect is a crash that can cause applications using the affected libraries to terminate unexpectedly, the buffer overflow condition creates opportunities for more severe exploitation. Attackers can leverage this vulnerability to overwrite critical memory locations including return addresses, function pointers, or other control structures, potentially allowing them to redirect program execution flow. This capability aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of how improper input validation can lead to arbitrary code execution. The vulnerability affects a wide range of applications that depend on FFmpeg or Libav for multimedia processing, including web browsers, media players, content management systems, and various multimedia applications.
Mitigation strategies for CVE-2011-4364 primarily focus on immediate software updates and patch management. Organizations should prioritize upgrading to patched versions of FFmpeg and Libav, specifically versions 0.5.7, 0.6.4, 0.7.9, 0.8.8, and their respective Libav counterparts. Additionally, implementing input validation measures at application layers can provide defense-in-depth protection, though this approach is less reliable than proper library updates. Security configurations should include disabling support for VMD file formats when not required, implementing sandboxing techniques for media processing, and deploying network-based intrusion detection systems to monitor for suspicious file delivery patterns. From an ATT&CK framework perspective, this vulnerability maps to technique T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter) as attackers can leverage the vulnerability to execute arbitrary code on target systems. System administrators should also consider implementing application whitelisting policies and monitoring for unusual process behavior that might indicate exploitation attempts, particularly focusing on memory corruption patterns that could indicate buffer overflow exploitation.