CVE-2019-9431 in Android
Summary
by MITRE
In Bluetooth, there is a possible out of bounds read due to a use after free. This could lead to remote information disclosure with heap information written to the log with System execution privileges needed. User interaction is not needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-109755179
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Analysis
by VulDB Data Team • 09/13/2020
The vulnerability identified as CVE-2019-9431 represents a critical security flaw within the Bluetooth implementation of Android 10 operating systems. This issue manifests as a use after free condition that occurs during Bluetooth protocol handling, specifically when processing certain Bluetooth packets or connections. The flaw exists in the underlying Bluetooth stack where memory management operations fail to properly validate object references after memory has been freed, creating opportunities for unauthorized access patterns. The vulnerability resides in the system-level Bluetooth services that handle wireless communication protocols and device pairing operations.
The technical exploitation of this vulnerability involves a memory corruption scenario where a freed memory block is accessed beyond its intended lifecycle, resulting in an out of bounds read condition. This particular flaw allows for remote information disclosure because the heap memory contents can be read and potentially exposed through log files generated by the system. The use after free condition typically occurs when the Bluetooth service attempts to access memory that has already been deallocated, causing the system to read beyond valid memory boundaries. The heap information that gets written to logs can contain sensitive data such as memory addresses, system pointers, or other confidential information that could aid attackers in further exploitation attempts.
From an operational impact perspective, this vulnerability presents a significant risk to Android 10 devices since it requires no user interaction for exploitation and can be triggered remotely through Bluetooth connections. The requirement for system execution privileges indicates that successful exploitation could allow attackers to access sensitive system information that might reveal memory layout details or other system internals. This information disclosure capability could enable attackers to perform more sophisticated attacks such as privilege escalation or memory corruption exploitation techniques. The vulnerability affects all Bluetooth-enabled Android 10 devices and poses a particular risk in environments where Bluetooth connectivity is frequently used or where devices are exposed to untrusted wireless networks.
The security implications of this vulnerability align with CWE-416 which describes the use after free condition, and can be mapped to ATT&CK technique T1059 which involves execution through system commands. The out of bounds read condition could potentially be leveraged to extract memory contents that might reveal system state information or assist in bypassing security mechanisms. Organizations should consider this vulnerability in their risk assessment frameworks and prioritize patching activities to mitigate exposure. The Android security team identified this issue through internal testing procedures and assigned it the Android ID A-109755179 for tracking purposes, indicating the severity and the need for immediate remediation. Device manufacturers and security teams should implement immediate mitigation strategies including firmware updates and security patches to address this use after free condition in the Bluetooth subsystem.
This vulnerability demonstrates the critical importance of proper memory management in system-level services and highlights the risks associated with wireless communication protocols that handle untrusted input data. The combination of remote exploitability and information disclosure capabilities makes this vulnerability particularly dangerous in mobile environments where devices frequently connect to unknown or untrusted networks. Security professionals should monitor for potential exploitation attempts and ensure that all Android 10 devices receive the appropriate security updates to address this memory corruption flaw.