CVE-2011-3623 in VLC Media Player
Summary
by MITRE
Multiple stack-based buffer overflows in VideoLAN VLC media player before 1.0.2 allow remote attackers to execute arbitrary code via (1) a crafted ASF file, related to the ASF_ObjectDumpDebug function in modules/demux/asf/libasf.c; (2) a crafted AVI file, related to the AVI_ChunkDumpDebug_level function in modules/demux/avi/libavi.c; or (3) a crafted MP4 file, related to the __MP4_BoxDumpStructure function in modules/demux/mp4/libmp4.c.
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Analysis
by VulDB Data Team • 04/10/2022
The vulnerability CVE-2011-3623 represents a critical stack-based buffer overflow issue affecting VideoLAN VLC media player versions prior to 1.0.2. This vulnerability resides in the media player's handling of various multimedia file formats including ASF, AVI, and MP4 containers, making it particularly dangerous due to the widespread use of these formats in digital media consumption. The flaw enables remote attackers to execute arbitrary code on systems running vulnerable versions of VLC, potentially leading to complete system compromise. These buffer overflows occur in the demultiplexer modules responsible for parsing and processing media container formats, specifically within the ASF_ObjectDumpDebug, AVI_ChunkDumpDebug_level, and __MP4_BoxDumpStructure functions.
The technical implementation of this vulnerability exploits the lack of proper bounds checking in the media parsing routines. When VLC processes maliciously crafted media files, the functions attempt to write data beyond the allocated stack buffer space, causing a stack overflow condition that can be leveraged by attackers to overwrite critical memory locations including return addresses and function pointers. The vulnerability manifests through three distinct attack vectors, each targeting different file format parsers within VLC's demultiplexer architecture. The ASF_ObjectDumpDebug function in libasf.c handles advanced streaming format files, AVI_ChunkDumpDebug_level in libavi.c processes audio video interleave containers, and __MP4_BoxDumpStructure in libmp4.c manages moving picture experts group format files. Each of these functions lacks adequate input validation and buffer size enforcement, creating predictable overflow conditions that attackers can exploit through carefully constructed malicious files.
The operational impact of CVE-2011-3623 extends beyond simple code execution, as it represents a significant threat to media playback security in environments where VLC serves as a primary media player. Attackers can craft malicious files that, when opened by vulnerable users, will trigger the buffer overflow conditions and provide remote code execution capabilities. This vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack memory regions, and falls under ATT&CK technique T1203 Exploitation for Client Execution. The attack requires no user interaction beyond opening the malicious file, making it particularly dangerous in social engineering scenarios. Organizations using VLC for media playback are at risk of unauthorized code execution, potential privilege escalation, and complete system compromise, especially in environments where users might encounter malicious media files through email attachments, web downloads, or peer-to-peer networks.
Mitigation strategies for CVE-2011-3623 focus primarily on upgrading to VLC version 1.0.2 or later, which contains patches addressing the identified buffer overflow conditions. System administrators should implement immediate patch management procedures to ensure all vulnerable installations are updated. Additional protective measures include implementing file type restrictions, deploying sandboxing mechanisms for media file handling, and monitoring for suspicious file access patterns. Network-level protections such as content filtering and email scanning can help prevent malicious media files from reaching end users. The vulnerability demonstrates the importance of input validation and bounds checking in multimedia processing libraries, emphasizing that security considerations must be integrated into all stages of software development. Organizations should also consider implementing security awareness training to educate users about the risks of opening untrusted media files, as the vulnerability can be exploited through social engineering attacks that trick users into opening maliciously crafted files.