CVE-2021-40566 in GPAC
Summary
by MITRE • 01/13/2022
A Segmentation fault casued by heap use after free vulnerability exists in Gpac through 1.0.1 via the mpgviddmx_process function in reframe_mpgvid.c when using mp4box, which causes a denial of service.
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Analysis
by VulDB Data Team • 01/15/2022
The vulnerability identified as CVE-2021-40566 represents a critical heap use after free condition within the Gpac multimedia framework version 1.0.1 and earlier. This flaw manifests specifically within the mpgviddmx_process function located in the reframe_mpgvid.c source file, creating a scenario where memory that has been previously deallocated is accessed or modified, leading to unpredictable behavior and system instability. The issue occurs when utilizing the mp4box utility, which is a core component of the Gpac suite designed for multimedia file processing and manipulation. Such vulnerabilities are particularly dangerous because they can be exploited to cause system crashes or potentially enable more sophisticated attacks if proper memory management controls are not in place.
The technical exploitation of this vulnerability occurs through a segmentation fault that results from improper memory handling during video processing operations. When the mpgviddmx_process function processes multimedia content, it manipulates heap memory structures that, under certain conditions, become freed but are subsequently accessed again. This heap use after free condition falls under the CWE-416 vulnerability category, which specifically addresses the use of freed memory, and represents a fundamental flaw in memory management practices within the affected software component. The segmentation fault that ensues directly impacts the mp4box utility's ability to process multimedia files, resulting in a denial of service condition that prevents legitimate users from accessing or processing their media content.
The operational impact of CVE-2021-40566 extends beyond simple service disruption to potentially compromise the integrity of multimedia processing workflows. Organizations relying on Gpac for video encoding, decoding, or file format conversion may experience unexpected application crashes when processing specific media files, leading to productivity losses and potential data processing interruptions. The vulnerability's presence in the mp4box utility means that any system utilizing this tool for multimedia processing is at risk, particularly in environments where automated media processing pipelines are in operation. Attackers could potentially leverage this vulnerability to repeatedly crash services, creating persistent denial of service conditions that would require system restarts and manual intervention to resolve, thereby impacting availability and operational continuity.
Mitigation strategies for CVE-2021-40566 should prioritize immediate patching of the affected Gpac version to the latest stable release where the heap use after free vulnerability has been addressed. System administrators should implement monitoring solutions to detect abnormal application behavior and segmentation faults that may indicate exploitation attempts. The vulnerability's classification under CWE-416 and its potential for denial of service attacks aligns with ATT&CK technique T1499.004, which focuses on network denial of service attacks through system resource exhaustion. Additionally, implementing proper memory management practices, including the use of memory debugging tools and regular code reviews focusing on heap allocation and deallocation patterns, can help prevent similar vulnerabilities from emerging in future development cycles. Organizations should also consider restricting access to the mp4box utility until patches are applied and implement input validation measures to reduce the attack surface for potential exploitation attempts.