CVE-2025-20657 in MT6765
Summary
by MITRE • 04/07/2025
In vdec, there is a possible permission bypass due to improper input validation. This could lead to local escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: ALPS09486425; Issue ID: MSV-2609.
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Analysis
by VulDB Data Team • 10/04/2025
The vulnerability identified as CVE-2025-20657 resides within the vdec component of a mobile operating system, specifically affecting the permission handling mechanisms that govern system-level access controls. This flaw represents a critical security weakness that could enable unauthorized privilege escalation, particularly when exploited by adversaries who have already gained system-level privileges. The vulnerability stems from inadequate input validation procedures that fail to properly sanitize or verify user-supplied data before processing within the vdec subsystem.
The technical implementation of this vulnerability manifests through improper validation of input parameters that flow through the video decoding component. When the system processes video data, the vdec module does not sufficiently validate the integrity and legitimacy of incoming data streams, allowing malicious actors to craft specially crafted inputs that bypass normal permission checks. This weakness creates a pathway for privilege escalation where an attacker with existing system privileges can leverage the flawed validation to gain elevated access rights. The vulnerability is particularly concerning because it operates without requiring user interaction, meaning exploitation can occur automatically once the attacker has established a foothold within the system.
From an operational perspective, this vulnerability significantly impacts system security posture by undermining the principle of least privilege enforcement. The flaw allows for potential unauthorized access to sensitive system resources and functionality that should remain restricted to authorized processes. Attackers could exploit this weakness to access privileged system components, potentially leading to complete system compromise or data exfiltration. The local escalation of privilege aspect means that even if an attacker cannot directly access system resources, they can use this vulnerability to elevate their privileges to full system level access, thereby bypassing multiple layers of security controls.
The security implications extend beyond immediate privilege escalation to encompass broader system integrity concerns. This vulnerability aligns with CWE-20, which describes improper input validation as a fundamental weakness in software security architecture. The attack surface for this vulnerability is particularly concerning given that it operates within a critical system component responsible for video decoding, which is frequently accessed by various applications and system services. The lack of user interaction requirement makes this vulnerability particularly dangerous as it can be exploited automatically during normal system operations without detection by traditional user-based monitoring systems.
Mitigation strategies should focus on implementing robust input validation mechanisms within the vdec subsystem, ensuring that all data streams are properly sanitized and validated before processing. The patch ALPS09486425 addresses this vulnerability by strengthening the validation procedures and implementing additional checks that prevent malformed inputs from bypassing permission controls. Organizations should prioritize deployment of this patch and conduct thorough security assessments to identify any potential exploitation attempts. Additionally, monitoring systems should be enhanced to detect anomalous behavior patterns that might indicate exploitation attempts, particularly focusing on unusual privilege escalation activities within the video decoding subsystem.
The vulnerability demonstrates the importance of maintaining strong security boundaries even within trusted system components, as highlighted by ATT&CK technique T1068 which covers privilege escalation through system binary manipulation. Security teams should implement comprehensive monitoring for privilege escalation events and ensure that all system components undergo rigorous security testing for input validation weaknesses. Regular security assessments of core system components like vdec are essential to prevent similar vulnerabilities from emerging in other critical subsystems, particularly as modern operating systems become increasingly complex and interconnected. The incident underscores the necessity of maintaining up-to-date security patches and implementing defense-in-depth strategies that protect against both known and emerging threats within system infrastructure.