CVE-2014-9626 in VLC Media Player
Summary
by MITRE
Integer underflow in the MP4_ReadBox_String function in modules/demux/mp4/libmp4.c in VideoLAN VLC media player before 2.1.6 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a box size less than 7.
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Analysis
by VulDB Data Team • 03/08/2022
The vulnerability identified as CVE-2014-9626 represents a critical integer underflow condition within the VideoLAN VLC media player software ecosystem. This flaw exists in the MP4_ReadBox_String function located in the modules/demux/mp4/libmp4.c file, specifically affecting versions prior to 2.1.6. The vulnerability arises from improper validation of box sizes during MP4 file parsing operations, creating a scenario where maliciously crafted media files can trigger unexpected behavior in the application's memory management systems.
The technical implementation of this vulnerability stems from the function's failure to properly handle cases where the box size parameter falls below the expected minimum threshold of seven bytes. When an attacker supplies a box size value that is less than seven, the integer underflow condition occurs, causing the application to miscalculate memory allocation or buffer boundaries. This type of flaw falls under the CWE-190 category of Integer Overflow or Wraparound, specifically manifesting as an underflow condition that can lead to memory corruption. The vulnerability operates at the demultiplexing layer of the media player, where it processes MP4 container format files and extracts audio and video streams for playback.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to potentially enable more severe consequences including arbitrary code execution or system compromise. Remote attackers can exploit this condition by crafting specially formatted MP4 files that contain malformed box structures with insufficient size parameters. When the vulnerable VLC player attempts to parse these malicious files, the integer underflow can cause heap corruption, stack corruption, or other memory-related issues that may be leveraged for privilege escalation or system instability. The vulnerability's potential for unspecified other impacts suggests that the memory corruption could be exploited to achieve code execution or information disclosure, making it particularly dangerous in environments where users might encounter untrusted media content.
The exploitation of this vulnerability aligns with several tactics described in the MITRE ATT&CK framework, particularly under the T1203 category of Exploitation for Credential Access and T1059.1.001 for Command and Scripting Interpreter. Attackers can leverage this flaw to execute malicious code through compromised media files, potentially gaining unauthorized access to systems or services running vulnerable versions of VLC. The vulnerability's remote nature means that attackers do not require local access to systems, making it particularly effective for widespread exploitation campaigns. Security professionals should note that this vulnerability demonstrates the importance of proper input validation and integer handling in multimedia processing libraries, as these components often handle untrusted data from external sources.
Mitigation strategies for CVE-2014-9626 primarily focus on immediate version updates to VLC media player 2.1.6 or later, which contain the necessary patches to address the integer underflow condition. Organizations should implement comprehensive patch management protocols to ensure all instances of VLC are updated promptly, particularly in environments where users might encounter untrusted media content. Additional protective measures include network-based filtering to block MP4 files from untrusted sources, implementation of sandboxing techniques for media processing, and regular security assessments of media handling components within applications. The vulnerability also underscores the necessity of input validation testing and static code analysis for multimedia libraries, as similar flaws may exist in other components that process structured data formats. Organizations should consider deploying intrusion detection systems that can identify suspicious media file patterns and implement automated scanning of media content before processing to prevent exploitation of similar integer underflow conditions in other software components.