CVE-2021-34071 in tsMuxer
Summary
by MITRE • 06/24/2021
Heap based buffer overflow in tsMuxer 2.6.16 allows attackers to cause a Denial of Service (DoS) by running the application with a crafted file.
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Analysis
by VulDB Data Team • 06/26/2021
The heap based buffer overflow vulnerability in tsMuxer version 2.6.16 represents a critical security flaw that enables remote attackers to execute denial of service attacks through maliciously crafted input files. This vulnerability specifically affects the multimedia processing capabilities of tsMuxer, a popular open source tool used for muxing and demuxing various video and audio formats including mpeg2, h264, h265, and various audio codecs. The flaw manifests when the application processes specially crafted media files that trigger improper memory handling during the parsing and processing stages of the multimedia data structures.
The technical implementation of this buffer overflow occurs within the heap memory management subsystem of tsMuxer where insufficient bounds checking is performed on user-supplied data during the parsing of container formats. When an attacker provides a malformed media file containing oversized data structures or malformed headers, the application fails to properly validate the input boundaries before copying data into heap allocated buffers. This leads to memory corruption that can result in application crashes, abrupt termination, or unpredictable behavior that effectively renders the tool unusable for legitimate users. The vulnerability is classified as a heap overflow due to the nature of memory allocation and deallocation patterns within the application's memory management routines.
The operational impact of this vulnerability extends beyond simple service disruption as it creates a persistent threat vector that can be exploited in automated attack scenarios. Attackers can craft malicious media files that will cause tsMuxer to crash whenever the application attempts to process them, leading to complete denial of service for systems that rely on this tool for multimedia processing tasks. This is particularly concerning in environments where tsMuxer is used for automated media conversion workflows, content distribution systems, or as part of larger multimedia processing pipelines. The vulnerability can be exploited by simply providing the malicious file to the application, making it accessible to both technical and non-technical attackers. Organizations using tsMuxer in production environments face significant risk of service interruption, potential data loss, and operational downtime that can impact business continuity and user experience.
Mitigation strategies for this vulnerability should focus on immediate patching and implementation of input validation controls. The primary remediation involves upgrading to tsMuxer version 2.6.17 or later where the heap overflow has been addressed through proper bounds checking and memory allocation validation. System administrators should implement strict file validation procedures that include content type verification and size limitations before processing media files through tsMuxer. Additionally, deploying application sandboxing techniques and restricting file processing capabilities can help contain the impact of potential exploitation attempts. Organizations should also consider implementing network segmentation and access controls to limit exposure of systems running tsMuxer to untrusted file inputs. The vulnerability demonstrates the importance of proper memory management practices and input validation in multimedia processing applications, aligning with CWE-121 heap-based buffer overflow classification and representing a typical attack pattern that could be mapped to ATT&CK technique T1499.004 for denial of service via resource exhaustion. This vulnerability underscores the critical need for robust software security practices in multimedia processing tools that handle untrusted input data, as these applications often serve as essential components in content delivery and media processing infrastructure.