CVE-2022-20115 in Android
Summary
by MITRE • 05/11/2022
In broadcastServiceStateChanged of TelephonyRegistry.java, there is a possible way to learn base station information without location permission due to a missing permission check. This could lead to local information disclosure with User execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-12 Android-12LAndroid ID: A-210118427
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Analysis
by VulDB Data Team • 05/13/2022
The vulnerability identified as CVE-2022-20115 resides within the Android telephony subsystem, specifically in the broadcastServiceStateChanged method of the TelephonyRegistry.java component. This flaw represents a critical permission bypass issue that allows unauthorized access to base station information without proper location permissions. The vulnerability manifests in Android 12 and Android 12L versions, affecting the core telephony services that manage cellular network connectivity and status updates. The underlying security weakness stems from the absence of a required permission check within the service state change broadcasting mechanism, creating an unintended information disclosure channel.
The technical implementation of this vulnerability exploits the lack of proper access controls within the telephony registry system. When service state changes occur, such as network registration updates or connection status modifications, the system broadcasts these events to registered listeners. However, the broadcastServiceStateChanged method fails to verify whether the requesting component possesses the necessary location permissions before exposing base station information. This oversight enables malicious applications or processes running with user execution privileges to intercept and extract cellular network identifiers including cell IDs, location area codes, and other base station metadata. The vulnerability operates at the system level where telephony services communicate with other components, making it particularly concerning for privacy and security implications.
From an operational perspective, this vulnerability creates significant risks for user privacy and device security. Attackers can leverage this flaw to perform passive location tracking by collecting base station information without requiring explicit location permissions, which violates fundamental privacy principles and Android's permission model. The information disclosure occurs in real-time during normal telephony operations, allowing continuous monitoring of user location through cellular network triangulation. This capability can be particularly dangerous when combined with other reconnaissance techniques, as it provides attackers with additional context for location-based attacks, tracking patterns, and potential social engineering opportunities. The vulnerability requires only user execution privileges, eliminating the need for escalated system permissions or root access, which makes it highly exploitable across various threat scenarios.
The security implications extend beyond simple information disclosure, as this vulnerability aligns with several ATT&CK framework techniques including T1059 for execution through user processes and T1071 for application layer protocols. From a CWE perspective, this represents a variant of CWE-284: Improper Access Control, specifically manifesting as missing permission checks in system services. The vulnerability also ties into broader privacy concerns related to location tracking and cellular network monitoring, potentially violating data protection regulations and privacy frameworks. Organizations and users should consider this vulnerability as part of a larger attack surface that includes other location-based tracking mechanisms and cellular network reconnaissance capabilities. The impact is particularly severe in environments where location privacy is critical, such as healthcare, financial services, or government operations where unauthorized tracking could lead to significant security breaches.
Mitigation strategies should focus on implementing proper permission checks within the telephony registry system and ensuring that all service state change broadcasts verify appropriate access controls. Android security patches should enforce strict permission validation for base station information access, requiring explicit location permissions before allowing such data to be exposed through the broadcast mechanism. System administrators should deploy the latest security updates and monitor for unauthorized applications attempting to access telephony services. Additionally, users should be educated about the importance of reviewing application permissions, particularly those related to location services, and should avoid installing untrusted applications that may exploit this vulnerability. The fix should involve strengthening the permission model to ensure that only components with proper location authorization can access cellular network information, thereby preventing unauthorized data leakage through the telephony subsystem.