CVE-2023-20992 in Android
Summary
by MITRE • 03/24/2023
In on_iso_link_quality_read of btm_iso_impl.h, there is a possible out of bounds read due to a missing bounds check. This could lead to local information disclosure in the Bluetooth server with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-13Android ID: A-260568750
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Analysis
by VulDB Data Team • 09/07/2025
The vulnerability identified as CVE-2023-20992 resides within the Bluetooth subsystem of Android 13 operating systems, specifically within the btm_iso_impl.h file where the on_iso_link_quality_read function fails to perform adequate bounds checking. This flaw represents a classic out-of-bounds read vulnerability that can be exploited to extract sensitive information from memory locations beyond the intended buffer boundaries. The issue is particularly concerning because it operates within the Bluetooth server component that runs with system-level execution privileges, meaning any successful exploitation could potentially expose confidential data to unauthorized parties.
The technical nature of this vulnerability stems from the absence of proper input validation within the Bluetooth ISO link quality reading functionality. When the system processes incoming Bluetooth communication data related to link quality metrics, it fails to verify that the data access operations remain within the allocated memory boundaries. This missing bounds check creates a condition where an attacker could craft malicious Bluetooth packets or manipulate existing communication parameters to trigger memory access beyond the intended buffer limits. The vulnerability manifests as an out-of-bounds read operation that could potentially expose kernel memory contents, including sensitive cryptographic keys, authentication tokens, or other confidential information stored in adjacent memory locations.
From an operational perspective, this vulnerability presents a significant risk to Android 13 devices since it requires only system-level execution privileges to exploit, eliminating the need for user interaction or elevated permissions. The Bluetooth server component typically runs with high privileges to manage wireless communications, making it an attractive target for attackers seeking to extract sensitive information without requiring additional attack vectors. The local information disclosure aspect means that an attacker with access to the device's Bluetooth functionality could potentially harvest confidential data from the system's memory space, potentially leading to credential theft, encryption key exposure, or other sensitive data compromise scenarios.
The implications of this vulnerability align with CWE-129, which specifically addresses improper bounds checking in software implementations. This weakness creates a pathway for information disclosure that can be leveraged by attackers to gain insights into system internals and potentially escalate their privileges further. According to ATT&CK framework categorization, this vulnerability maps to T1059.001 for command and script interpreter usage and T1566 for credential access through network services, as the Bluetooth subsystem represents a primary attack surface for information extraction. The exploitation of this vulnerability could enable attackers to gather intelligence about the device's security configuration, potentially aiding in subsequent attacks targeting other system components.
Mitigation strategies should focus on implementing proper bounds checking within the Bluetooth subsystem, particularly in the btm_iso_impl.h file where the vulnerability originates. Android security patches should include comprehensive memory validation routines that ensure all data access operations remain within allocated buffer boundaries. Device manufacturers should prioritize immediate deployment of security updates to address this vulnerability, as the combination of system execution privileges and local access requirements makes it particularly dangerous. Additionally, network administrators should monitor for any unusual Bluetooth communication patterns that might indicate exploitation attempts, while security teams should implement memory protection mechanisms such as stack canaries or address space layout randomization to reduce the effectiveness of potential exploitation attempts.