CVE-2021-41459 in MP4Box
Summary
by MITRE • 10/01/2021
There is a stack buffer overflow in MP4Box v1.0.1 at src/filters/dmx_nhml.c:1008 in the nhmldmx_send_sample() function szXmlFrom parameter which leads to a denial of service vulnerability.
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Analysis
by VulDB Data Team • 10/08/2021
The vulnerability identified as CVE-2021-41459 represents a critical stack buffer overflow flaw within the MP4Box media processing utility version 1.0.1. This issue manifests in the nhmldmx_send_sample() function located at src/filters/dmx_nhml.c line 1008, where the szXmlFrom parameter is processed without adequate bounds checking. The MP4Box utility is part of the GPAC multimedia framework, which serves as a comprehensive solution for handling various multimedia formats including mp4, 3gp, and other container formats. The vulnerability arises when the application attempts to process malformed or maliciously crafted xml data within the nhml (Nero H.264) demuxer component, specifically during the sample delivery phase of media processing.
The technical implementation of this vulnerability stems from improper memory management practices where the szXmlFrom parameter receives data that exceeds the allocated stack buffer size. This condition creates a classic stack-based buffer overflow scenario where adjacent memory locations become overwritten with attacker-controlled data. The flaw is particularly dangerous because it occurs during the media demultiplexing process when the application is parsing xml metadata embedded within Nero H.264 files. The vulnerability can be triggered when the application encounters specially crafted nhml files that contain oversized xml data structures, causing the stack buffer to overflow and corrupt adjacent memory regions including return addresses and local variables.
Operationally, this vulnerability presents a significant denial of service risk that can be exploited by remote attackers to crash the MP4Box application or potentially execute arbitrary code depending on memory layout and exploitation conditions. The impact extends beyond simple service disruption as the vulnerability affects the core media processing functionality of the GPAC framework, which is widely used in multimedia applications, streaming platforms, and content delivery systems. Attackers could leverage this flaw to cause application crashes, system instability, or in more sophisticated scenarios potentially achieve remote code execution through careful exploitation of the buffer overflow conditions. The vulnerability affects systems where MP4Box is deployed for media processing tasks, including content management systems, streaming servers, and multimedia applications that rely on the GPAC framework for format conversion and processing.
Mitigation strategies for CVE-2021-41459 should prioritize immediate patch deployment from the GPAC project maintainers who have addressed this vulnerability in subsequent releases. Organizations should implement restrictive file access controls and input validation measures to prevent processing of untrusted media files, particularly those from unknown or unverified sources. Network-based mitigations could include implementing content filtering rules to block suspicious nhml file types or implementing sandboxing mechanisms to isolate media processing operations. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which is classified under the broader category of memory safety issues in software development practices. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 Command and Scripting Interpreter: JavaScript and T1499.004 Network Denial of Service, as it enables both service disruption and potential code execution through crafted media content. System administrators should also consider implementing automated monitoring solutions to detect abnormal application behavior or crash patterns that may indicate exploitation attempts. Regular security assessments of multimedia processing pipelines and input validation controls should be conducted to ensure comprehensive protection against similar buffer overflow vulnerabilities in related components of the GPAC framework.