CVE-2021-1006 in Android
Summary
by MITRE • 12/15/2021
In several functions of DatabaseManager.java, there is a possible leak of Bluetooth MAC addresses due to log information disclosure. This could lead to local information disclosure with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-12Android ID: A-183961974
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Analysis
by VulDB Data Team • 12/18/2021
The vulnerability identified as CVE-2021-1006 represents a critical information disclosure flaw within Android's Bluetooth subsystem that manifests through improper logging of sensitive MAC addresses. This vulnerability exists in the DatabaseManager.java component of the Android operating system, specifically affecting Android 12 builds. The flaw stems from the improper handling of Bluetooth device identifiers during database operations, where MAC addresses are inadvertently written to system logs without adequate sanitization or access controls. This type of vulnerability falls under the CWE-209 category of "Information Exposure Through Logging" and represents a significant security risk as it can expose sensitive device identification information to unauthorized parties.
The technical implementation of this vulnerability occurs within the DatabaseManager.java file where multiple functions process Bluetooth MAC addresses without proper input validation or output sanitization. When Bluetooth devices are discovered, paired, or managed through the database operations, the MAC addresses are logged in plain text format to system log files that may be accessible to applications with system-level privileges. This logging behavior creates a persistent exposure of device identifiers that can be leveraged by malicious actors to track device movements, correlate device usage patterns, or perform targeted attacks. The vulnerability requires system execution privileges for exploitation, indicating that it can be triggered by applications that have been granted elevated permissions, though the actual disclosure occurs at the system level where logging mechanisms operate.
The operational impact of CVE-2021-1006 extends beyond simple information disclosure as it creates persistent tracking capabilities for Bluetooth devices within the Android ecosystem. Attackers who can execute code with system privileges can exploit this vulnerability to extract Bluetooth MAC addresses from system logs, potentially enabling them to perform device fingerprinting, location tracking, or correlation attacks across different networks and time periods. The vulnerability's exploitation does not require user interaction, making it particularly dangerous as it can be triggered automatically during normal device operations. This type of vulnerability aligns with ATT&CK technique T1083 (File and Directory Discovery) and T1071.004 (Application Layer Protocol: DNS) as attackers can use the disclosed MAC addresses to build comprehensive device profiles and potentially identify specific users or locations through Bluetooth device tracking.
Mitigation strategies for this vulnerability should focus on implementing proper logging sanitization and access controls within the Android system. System administrators and device manufacturers should ensure that Bluetooth MAC addresses are not logged in plain text format and that logging mechanisms properly sanitize sensitive information before writing to system logs. The Android security team has addressed this issue through system updates that implement proper MAC address obfuscation in logging operations. Additionally, implementing least privilege principles for applications that require access to Bluetooth functionality can reduce the attack surface. Organizations should also consider implementing log monitoring systems that can detect and alert on suspicious logging patterns that may indicate information disclosure attempts. The vulnerability demonstrates the importance of secure coding practices in mobile operating systems and highlights the need for comprehensive security testing of logging mechanisms that handle sensitive device identifiers.