CVE-2026-21072 in Samsung
Summary
by MITRE • 08/10/2026
Improper input validation in VC1 codec in libsavsvc.so prior to SMR Aug-2026 Release 1 allows local attackers to write out-of-bounds memory.
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Analysis
by VulDB Data Team • 08/10/2026
This vulnerability represents a critical buffer overflow condition within the VC1 codec implementation in the libsavsvc.so library, affecting systems prior to the SMR August 2026 release. The flaw stems from inadequate input validation mechanisms that fail to properly sanitize or verify the boundaries of data streams processed by the video compression decoding component. When maliciously crafted media files are processed through this vulnerable codec, the application fails to enforce proper memory access limits during frame reconstruction operations, creating opportunities for attackers to write beyond allocated memory boundaries.
The technical exploitation occurs when the VC1 decoder encounters malformed input data that exceeds expected parameter ranges or frame dimensions. This improper validation allows attackers to construct specially crafted video content that triggers memory corruption during decoding operations. The vulnerability specifically affects the handling of variable length coding elements and macroblock processing within the codec's decompression pipeline, where insufficient boundary checks permit arbitrary memory writes that can overwrite adjacent memory regions including stack variables, heap allocations, or critical program structures.
From an operational impact perspective, this vulnerability enables local privilege escalation attacks where adversaries can leverage the out-of-bounds write condition to execute arbitrary code with the privileges of the affected process. The attack surface is particularly concerning in environments where users can process untrusted video content, such as media processing servers, content management systems, or applications handling user-uploaded multimedia files. Attackers may exploit this weakness to gain unauthorized access to system resources, potentially leading to complete system compromise and persistent backdoor installation.
The vulnerability maps directly to CWE-121 and CWE-787 which specifically address stack-based and heap-based buffer overflow conditions, respectively. According to ATT&CK framework, this represents a privilege escalation technique under T1068 with potential lateral movement capabilities through code execution. Organizations should immediately implement patch management procedures to deploy the SMR August 2026 release or apply vendor-specific mitigations. Additional defensive measures include input sanitization at multiple layers, memory protection mechanisms such as stack canaries and address space layout randomization, and network segmentation to limit exposure of vulnerable services to untrusted inputs. Regular security assessments should verify proper implementation of bounds checking and input validation across all multimedia processing components within the system architecture.