CVE-2020-0085 in Android
Summary
by MITRE
In setBluetoothTethering of PanService.java, there is a possible permission bypass due to a missing permission check. This could lead to local escalation of privilege to activate tethering with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-10Android ID: A-134487438
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Analysis
by VulDB Data Team • 04/11/2024
The vulnerability identified as CVE-2020-0085 represents a critical permission bypass flaw within Android's Bluetooth tethering functionality, specifically affecting Android 10 implementations. This issue resides in the PanService.java component where the setBluetoothTethering method fails to perform adequate permission verification before allowing Bluetooth tethering activation. The flaw stems from a missing permission check that should validate whether the calling process possesses the necessary privileges to modify network tethering settings. This oversight creates a pathway for malicious applications to bypass the standard permission model and activate Bluetooth tethering without proper authorization, effectively undermining the Android security framework's privilege separation mechanisms.
The technical exploitation of this vulnerability demonstrates a clear violation of the principle of least privilege, where unauthorized processes can manipulate network connectivity settings through Bluetooth interfaces. The flaw operates at the system service level where Bluetooth tethering configuration is managed, allowing an attacker with minimal privileges to escalate their capabilities within the Android operating system. This permission bypass enables local privilege escalation, meaning that an application with basic user permissions can potentially gain elevated system privileges to control network tethering functionality. The vulnerability's impact is particularly concerning because it eliminates the need for user interaction, making exploitation entirely automated and invisible to end users.
From an operational standpoint, this vulnerability poses significant security risks to Android devices, as it allows unauthorized activation of Bluetooth tethering which can lead to data exfiltration, network monitoring, and potential lateral movement within corporate environments. The attack surface extends beyond simple tethering activation to include potential network reconnaissance activities and unauthorized data transmission through Bluetooth interfaces. This flaw aligns with CWE-284, which describes improper access control vulnerabilities, and can be mapped to ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation" within the adversary tactics framework. The vulnerability's nature suggests it could be leveraged by malware to establish persistent network access or to create covert communication channels through Bluetooth tethering.
The mitigation strategies for CVE-2020-0085 should prioritize immediate patch deployment from Google, as the vulnerability exists within core Android system services that cannot be adequately protected through application-level security measures. System administrators and device manufacturers must ensure that all Android 10 devices receive the relevant security updates that implement proper permission validation in the PanService.java component. Additional protective measures include implementing application sandboxing, monitoring Bluetooth tethering activation events through security information and event management systems, and conducting regular security audits of system services to identify similar permission bypass vulnerabilities. Organizations should also consider network-level monitoring to detect anomalous Bluetooth tethering activities that could indicate exploitation of this vulnerability. The fix typically involves adding explicit permission checks before allowing Bluetooth tethering operations, ensuring that only processes with proper network management privileges can invoke these functions, thereby restoring the intended security boundaries within the Android operating system.