CVE-2016-3760 in Android
Summary
by MITRE
Bluetooth in Android 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-07-01 allows local users to gain privileges by establishing a pairing that remains present during a session of the primary user, aka internal bug 27410683.
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Analysis
by VulDB Data Team • 02/22/2019
This vulnerability resides in the Bluetooth implementation of Android operating systems affecting versions 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before the 2016-07-01 security update. The flaw represents a privilege escalation issue that exploits the Bluetooth pairing mechanism to allow local attackers to gain elevated privileges within the system. The vulnerability specifically occurs when a malicious device establishes a Bluetooth pairing that persists throughout a primary user session, creating a persistent backdoor for unauthorized access. This represents a critical security weakness in the Android Bluetooth stack that directly violates the principle of least privilege and user authentication mechanisms.
The technical implementation of this vulnerability stems from improper handling of Bluetooth pairing sessions within the Android framework. When a device establishes a successful Bluetooth pairing with an Android device, the system should properly validate the pairing context and ensure that such connections cannot be leveraged for privilege escalation. However, the flaw allows a local attacker with physical access to establish a persistent pairing relationship that can be exploited during active user sessions. This creates a scenario where the pairing relationship remains active and trusted throughout the user session, enabling the attacker to potentially execute privileged operations that should normally be restricted to system-level processes or authenticated users.
From an operational impact perspective, this vulnerability presents a significant threat to Android device security as it allows local privilege escalation without requiring network connectivity or complex attack vectors. The attack can be executed simply by establishing a Bluetooth pairing with a device that has been configured to maintain persistent connections. This vulnerability particularly affects enterprise environments where Android devices are used for sensitive operations, as it could enable attackers to gain system-level access to devices that are otherwise protected by standard user authentication mechanisms. The persistent nature of the pairing relationship means that once exploited, the vulnerability can maintain access across device reboots and session transitions, making it particularly dangerous for long-term compromise scenarios.
The vulnerability aligns with CWE-284, which addresses improper access control issues in software systems, and represents a clear violation of the principle of least privilege. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and can be leveraged to achieve initial access and persistence within Android environments. Organizations should implement immediate mitigations including applying the relevant Android security patches released in the 2016-07-01 update cycle, disabling Bluetooth pairing when not actively required, and implementing network segmentation to limit potential attack vectors. Additionally, security monitoring should be enhanced to detect unusual Bluetooth pairing activities and persistent connection patterns that could indicate exploitation attempts. The vulnerability demonstrates the importance of proper Bluetooth security implementation in mobile operating systems and highlights the need for comprehensive security testing of system-level components that handle user authentication and access control.