CVE-2021-35346 in tsMuxer
Summary
by MITRE • 12/03/2021
tsMuxer v2.6.16 was discovered to contain a heap-based buffer overflow via the function HevcSpsUnit::short_term_ref_pic_set(int) in hevc.cpp.
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Analysis
by VulDB Data Team • 05/03/2026
The vulnerability CVE-2021-35346 represents a critical heap-based buffer overflow in tsMuxer version 2.6.16, specifically within the HevcSpsUnit::short_term_ref_pic_set function located in the hevc.cpp source file. This flaw exists in the handling of HEVC (H.265) video stream processing where the application fails to properly validate input data when parsing short term reference picture sets. The buffer overflow occurs when the application attempts to write data beyond the allocated memory boundaries, potentially allowing malicious actors to manipulate memory layout and execute arbitrary code. This vulnerability directly impacts the integrity and availability of systems processing HEVC video content through tsMuxer.
The technical implementation of this vulnerability stems from inadequate bounds checking within the video parameter set parsing logic. When tsMuxer processes HEVC streams, it encounters a specific parsing scenario where the short_term_ref_pic_set function does not properly validate the size of reference picture sets against allocated buffer space. This weakness creates an exploitable condition where crafted malicious input can cause the application to write beyond its intended memory allocation, leading to memory corruption. The vulnerability is classified as a heap-based buffer overflow under CWE-121, which specifically addresses conditions where data is written beyond the boundaries of heap-allocated buffers. The flaw demonstrates a classic memory safety issue that can be exploited through controlled input manipulation.
The operational impact of CVE-2021-35346 extends beyond simple application crashes, presenting significant security risks for systems processing video content. Attackers could potentially leverage this vulnerability to execute arbitrary code on systems running affected versions of tsMuxer, particularly in environments where the software processes untrusted video inputs. The vulnerability affects multimedia processing workflows, digital asset management systems, and content distribution platforms that utilize tsMuxer for HEVC stream handling. This flaw could be exploited in various attack scenarios including targeted attacks against media processing servers, supply chain compromises through malicious video files, or automated exploitation in environments where the software processes user-uploaded content. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation could enable attackers to execute arbitrary commands on compromised systems.
Mitigation strategies for this vulnerability require immediate remediation through software updates to versions that address the buffer overflow condition. System administrators should prioritize patching tsMuxer installations to versions containing the fixed implementation of the HevcSpsUnit::short_term_ref_pic_set function with proper input validation and bounds checking. Additionally, implementing input sanitization measures and restricting processing of untrusted video content can provide defense-in-depth protection. Network segmentation and access controls should be enforced to limit exposure of systems running tsMuxer to potentially malicious inputs. Organizations should also consider deploying intrusion detection systems that can identify exploitation attempts targeting this specific vulnerability. The fix typically involves implementing proper boundary checks and input validation within the affected parsing function, ensuring that reference picture set sizes are validated against allocated buffer capacities before any memory operations occur.