CVE-2025-21011 in Galaxy Watch
Summary
by MITRE • 08/06/2025
Improper access control in SemSensorService for Galaxy Watch prior to SMR Aug-2025 Release 1 allows local attackers to access sensitive information related to motion and body sensors.
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Analysis
by VulDB Data Team • 08/06/2025
The vulnerability identified as CVE-2025-21011 represents a critical access control flaw within the SemSensorService component of Samsung Galaxy Watch devices prior to the SMR August 2025 security release. This issue affects the fundamental security architecture of the wearable device by allowing unauthorized local access to sensitive sensor data. The vulnerability resides in the improper implementation of access controls that should normally restrict access to motion and body sensor information to authorized applications and system processes only. The flaw enables malicious local actors to bypass intended security boundaries and extract confidential biometric and movement data from the device's sensor ecosystem.
The technical implementation of this vulnerability stems from inadequate privilege validation and authentication checks within the SemSensorService daemon. This service is responsible for managing and exposing sensor data from various hardware components including accelerometers, gyroscopes, heart rate monitors, and other biometric sensors. The improper access control mechanism fails to properly verify the identity and authorization level of requesting processes, allowing any locally running application to potentially access sensitive sensor readings without proper authentication. This represents a direct violation of the principle of least privilege and demonstrates a critical failure in the device's security model for handling sensitive personal data.
The operational impact of this vulnerability extends beyond simple data exposure to encompass potential privacy violations and security risks for users of affected Galaxy Watch devices. Local attackers with malicious applications installed on the device can access continuous streams of motion data, heart rate measurements, and other biometric information that could reveal personal habits, health conditions, and behavioral patterns. The implications are particularly concerning given that wearable devices are increasingly used for health monitoring and personal fitness tracking, where such data could be exploited for identity theft, insurance fraud, or targeted advertising. The vulnerability affects the device's ability to maintain data confidentiality and integrity as defined by security frameworks such as the Common Weakness Enumeration CWE-284 which specifically addresses improper access control vulnerabilities.
Security mitigations for this vulnerability should focus on implementing proper access control mechanisms within the SemSensorService component. Device manufacturers should enforce strict authentication and authorization checks before allowing access to sensor data, ensuring that only trusted system processes and authorized applications can retrieve sensitive information. The security model should incorporate role-based access controls and proper privilege separation to prevent unauthorized data access. Additionally, regular security audits and code reviews should be conducted to identify similar access control flaws in other system components. This vulnerability aligns with ATT&CK technique T1070.004 which involves the use of file and directory permissions to gain access to sensitive information, demonstrating how improper access controls can create persistent security weaknesses in mobile device environments. Users should be advised to install the SMR August 2025 security update immediately to remediate this vulnerability and protect their personal health data from unauthorized access.