CVE-2023-20986 in Android
Summary
by MITRE • 03/24/2023
In btm_ble_clear_resolving_list_complete of btm_ble_privacy.cc, there is a possible out of bounds read due to a missing bounds check. This could lead to local information disclosure with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-13Android ID: A-255304475
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Analysis
by VulDB Data Team • 09/07/2025
The vulnerability identified as CVE-2023-20986 resides within the Bluetooth stack implementation of Android 13 systems, specifically in the btm_ble_clear_resolving_list_complete function located in the btm_ble_privacy.cc source file. This issue represents a classic out-of-bounds read condition that occurs when the system fails to validate array indices before accessing memory locations. The flaw manifests during Bluetooth privacy management operations where the system attempts to clear the resolving list, a critical component for managing Bluetooth device identities and privacy settings. The absence of proper bounds checking allows malicious actors to potentially access memory regions outside the intended array boundaries, creating a pathway for information disclosure.
The technical exploitation of this vulnerability requires an attacker to possess system-level execution privileges, indicating that the flaw cannot be triggered through standard user interactions or remote attacks. This requirement for system execution privileges aligns with the ATT&CK framework's privilege escalation techniques, where adversaries must first gain elevated access before leveraging such memory corruption vulnerabilities. The vulnerability maps to CWE-129, which specifically addresses insufficient checking of string lengths or buffer sizes, and CWE-787, which covers out-of-bounds write operations. These classifications emphasize the fundamental nature of the flaw as a memory safety issue that can potentially be exploited to read sensitive data from adjacent memory locations.
The operational impact of this vulnerability extends beyond simple information disclosure, as it could potentially expose sensitive Bluetooth privacy data, including device identifiers, connection parameters, and potentially other confidential information stored within the Bluetooth stack's memory structures. Attackers could leverage this condition to reconstruct device privacy settings, track device movements through Bluetooth signals, or extract other sensitive metadata that could be used for further attacks. The Android security model's reliance on system-level privileges for exploitation suggests that this vulnerability would primarily affect devices where malicious applications or processes have already gained root access or where system-level exploits have been successfully deployed.
Mitigation strategies for CVE-2023-20986 should focus on implementing comprehensive bounds checking mechanisms within the Bluetooth privacy management functions, particularly in the btm_ble_clear_resolving_list_complete routine. Security patches should enforce strict validation of array indices before memory access operations, ensuring that all buffer operations remain within defined boundaries. Device manufacturers should prioritize updating Android 13 systems with patches that address the specific bounds checking deficiencies in the Bluetooth stack implementation. Additionally, runtime memory protection mechanisms such as stack canaries, address space layout randomization, and memory integrity checks should be implemented to provide additional defense-in-depth measures against similar vulnerabilities. The fix should align with Android security best practices and follow the principle of least privilege, ensuring that Bluetooth privacy operations cannot access unauthorized memory regions regardless of the execution context.