CVE-2007-3329 in Xvid
Summary
by MITRE
Multiple array index errors in the (1) get_intra_block, (2) get_inter_block_h263, and (3) get_inter_block_mpeg functions in src/bitstream/mbcoding.c in Xvid 1.1.2 allow remote attackers to execute arbitrary code via a crafted (a) Avi, (b) H.263, or (c) MPEG file.
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Analysis
by VulDB Data Team • 07/24/2019
The vulnerability described in CVE-2007-3329 represents a critical security flaw within the Xvid video codec library version 1.1.2 which affects the processing of video files in multiple formats including AVI, H.263, and MPEG. This issue stems from multiple array index errors located in the bitstream decoding functions responsible for handling intra and inter block data during video compression and decompression operations. The affected functions get_intra_block, get_inter_block_h263, and get_inter_block_mpeg in the src/bitstream/mbcoding.c source file demonstrate improper bounds checking that allows attackers to manipulate memory access patterns through crafted video files. These array index errors create opportunities for buffer overflows and memory corruption that can be exploited to execute arbitrary code on systems processing the malicious media content.
The technical implementation of this vulnerability involves the manipulation of video bitstream data to trigger out-of-bounds memory access during the decoding process. When the Xvid library processes specially crafted video files, the get_intra_block function fails to properly validate array indices when handling intra-coded video blocks, while get_inter_block_h263 and get_inter_block_mpeg functions suffer from similar issues when processing inter-coded blocks in H.263 and MPEG formats respectively. The lack of proper input validation and bounds checking in these functions allows attackers to provide malicious data that causes the decoder to access memory locations outside the intended array boundaries, potentially leading to stack corruption, heap corruption, or other memory-related vulnerabilities that can be leveraged for code execution.
The operational impact of CVE-2007-3329 extends beyond simple code execution as it represents a remote code execution vulnerability that can be exploited through various media delivery channels. Attackers can craft malicious AVI, H.263, or MPEG files that, when processed by vulnerable systems, will trigger the memory corruption conditions. This vulnerability affects a wide range of applications that utilize the Xvid codec for video processing, including media players, video editing software, content management systems, and web browsers that support these video formats. The remote nature of the exploit means that users can be compromised simply by opening or playing the malicious video content, making this vulnerability particularly dangerous in environments where automated media processing occurs or where users have no control over the media content they encounter.
The vulnerability aligns with CWE-129, which describes improper validation of array indices, and represents a classic example of buffer overflow conditions that can be exploited through malformed input data. From an ATT&CK perspective, this vulnerability maps to techniques involving code injection and privilege escalation through media processing exploits. The attack surface includes any system that processes video content using the affected Xvid library version, making it a significant concern for organizations running media servers, content delivery networks, or any infrastructure that handles user-uploaded video content. The exploitation requires no special privileges on the target system beyond the ability to process the malicious media files, which makes it particularly dangerous in automated processing environments. Organizations should prioritize patching affected systems and implementing content filtering mechanisms to prevent exploitation of this vulnerability.
Mitigation strategies for CVE-2007-3329 include immediate upgrading to Xvid versions that contain patches for the identified array index errors, implementing strict input validation for all video content processed by affected applications, and deploying network-based intrusion detection systems that can identify suspicious video file patterns. System administrators should also consider implementing sandboxing techniques for video processing applications and establishing secure media handling protocols that prevent automatic execution of potentially malicious content. The vulnerability demonstrates the importance of proper bounds checking in cryptographic and media processing libraries, where input validation is critical to prevent memory corruption exploits that can lead to complete system compromise.