CVE-2020-27032 in Android
Summary
by MITRE • 12/15/2020
In getRadioAccessFamily of PhoneInterfaceManager.java, there is a possible read of privileged data due to a missing permission check. This could lead to local information disclosure of radio data with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-150857259
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 12/18/2020
The vulnerability described in CVE-2020-27032 resides within the Android operating system's PhoneInterfaceManager.java component, specifically in the getRadioAccessFamily method. This issue represents a critical permission bypass flaw that allows unauthorized access to sensitive radio communication data without requiring any additional privileges or user interaction. The vulnerability is classified under CWE-284 which denotes inadequate access control mechanisms, specifically manifesting as improper privilege management within the telecommunications framework of Android devices.
The technical flaw occurs when the getRadioAccessFamily method fails to perform proper permission validation before exposing radio access family information. This method is part of the telephony subsystem that manages communication between the device and various radio access networks including GSM, CDMA, LTE, and 5G. The missing permission check creates a pathway for malicious applications to extract privileged radio data that should only be accessible to system-level components or applications with appropriate telephony permissions. This type of information disclosure can reveal critical details about the device's cellular capabilities, network registration status, and radio configuration parameters that could be leveraged for further attacks or analysis.
The operational impact of this vulnerability extends beyond simple information disclosure as it provides attackers with valuable insights into the device's telecommunications infrastructure. An attacker could potentially determine the device's supported radio technologies, current network connections, and registration states which could aid in crafting more sophisticated attacks against the device's communication channels. The vulnerability's exploitation requires no user interaction, making it particularly dangerous as it can be triggered automatically when the affected method is called by malicious applications. This characteristic aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, as the vulnerability can be used to gain deeper insights into the device's telecommunications capabilities for subsequent attacks.
The security implications of this vulnerability are significant for Android 11 devices, as it represents a fundamental breakdown in the operating system's permission model for telephony services. The Android security model relies heavily on proper permission enforcement to isolate sensitive system components from potentially malicious applications. This flaw undermines that isolation by allowing unauthorized access to radio family data that could be used to fingerprint devices, identify network configurations, or even predict and exploit other vulnerabilities in the telecommunications stack. The vulnerability's classification as a local information disclosure means that any application with basic execution privileges could potentially access this data, making it a serious concern for device security and user privacy. Mitigation strategies should focus on implementing proper permission checks in the PhoneInterfaceManager component and ensuring that all telephony-related methods enforce appropriate access controls to prevent unauthorized data exposure.