CVE-2026-21071 in Samsung
Summary
by MITRE • 08/10/2026
Improper input validation in MPEG4 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 memory safety issue within the MPEG4 codec implementation in the libsavsvc.so library component that affects systems prior to the SMR August 2026 security release. The flaw stems from inadequate input validation mechanisms that fail to properly sanitize or verify incoming data streams before processing them through the codec's decoding functions. Attackers can exploit this weakness by crafting maliciously formatted MPEG4 media content that triggers buffer overflow conditions during the decoding process, potentially allowing arbitrary code execution or system compromise.
The technical implementation of this vulnerability aligns with common software security weaknesses documented under CWE-129 and CWE-787, which specifically address insufficient input validation and out-of-bounds write operations. When the MPEG4 codec processes malformed input data, it fails to perform proper bounds checking on buffer allocations, enabling attackers to overwrite adjacent memory regions beyond the intended data structures. This type of vulnerability is particularly dangerous because it can be triggered through legitimate media processing functions that applications rely upon for normal operation.
From an operational perspective, this vulnerability exposes systems to local privilege escalation attacks where attackers with minimal system access can leverage the codec's processing capabilities to gain elevated privileges or cause denial-of-service conditions. The impact extends beyond simple memory corruption as it can potentially enable attackers to execute arbitrary code within the context of the affected application, making it a high-severity concern for any system that processes MPEG4 media content. Network-based exploitation becomes possible if the vulnerable codec is used in web applications or media processing pipelines that accept user-uploaded content.
The attack surface for this vulnerability includes any application or service that utilizes the libsavsvc.so library for video processing, including multimedia frameworks, streaming services, and embedded systems that handle MPEG4 format files. Security professionals should consider implementing runtime protections such as address space layout randomization and stack canaries to mitigate potential exploitation attempts. Additionally, organizations should prioritize updating their systems to the SMR August 2026 release or applying equivalent patches that implement proper input validation mechanisms and bounds checking procedures.
Mitigation strategies should focus on immediate patch deployment alongside application-level controls that validate all incoming media content before processing, implementing strict input sanitization routines, and monitoring for unusual memory access patterns. The vulnerability demonstrates the importance of robust codec security measures as outlined in industry best practices for multimedia processing security, particularly in environments where untrusted media content may be processed. Regular security assessments of multimedia libraries and codecs should be conducted to identify similar validation weaknesses that could enable similar exploitation vectors.
This type of vulnerability also intersects with ATT&CK technique T1059.007 which covers the use of system services and libraries for code execution, as attackers can leverage the compromised codec functionality to establish persistence or escalate privileges within affected systems. The remediation approach should include comprehensive testing of patched versions to ensure that legitimate functionality remains intact while eliminating the memory safety gaps that enable exploitation. Organizations should also consider implementing network segmentation and access controls to limit potential attack vectors that could leverage this vulnerability in broader system compromise scenarios.