CVE-2023-20984 in Android
Summary
by MITRE • 03/24/2023
In ParseBqrLinkQualityEvt of btif_bqr.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-242993878
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Analysis
by VulDB Data Team • 09/07/2025
The vulnerability identified as CVE-2023-20984 represents a critical out-of-bounds read flaw within the Bluetooth Quality Report (BQR) subsystem of Android 13 operating systems. This issue resides in the ParseBqrLinkQualityEvt function located in the btif_bqr.cc source file, where developers have failed to implement proper bounds checking mechanisms. The absence of input validation creates a scenario where maliciously crafted Bluetooth data could trigger memory access violations that extend beyond intended buffer boundaries.
The technical nature of this vulnerability aligns with CWE-129, which specifically addresses insufficient bounds checking in software implementations. The flaw operates at the system level where Bluetooth communication protocols interact with the underlying operating system components, making it particularly dangerous as it requires only system execution privileges to exploit. This means that an attacker with local access to a device running Android 13 could potentially leverage this vulnerability to extract sensitive information from system memory, including potentially confidential data that should remain protected within the device's secure execution environment.
From an operational perspective, this vulnerability presents significant risk to Android 13 devices as it enables local information disclosure without requiring user interaction, which is characteristic of a privilege escalation vulnerability. The exploitation process involves sending specially crafted Bluetooth Quality Report data that causes the ParseBqrLinkQualityEvt function to read memory locations beyond the allocated buffer boundaries. This could result in exposure of kernel memory contents, system configuration details, or other sensitive information that could be used for further attacks or system compromise.
The impact of this vulnerability extends beyond simple information disclosure as it represents a potential pathway for more sophisticated attacks within the Android security model. The fact that it requires system execution privileges indicates that it operates at a level where it can access protected system resources, potentially allowing for the extraction of credentials, encryption keys, or other sensitive data that should remain isolated from regular application access. This aligns with ATT&CK technique T1059.001 for command and scripting interpreter, as exploitation could enable unauthorized command execution within the system context.
Mitigation strategies for CVE-2023-20984 should prioritize immediate patch deployment from Google, as the vulnerability affects the core Bluetooth subsystem that is integral to device functionality. System administrators should ensure that all Android 13 devices receive the relevant security updates that address the missing bounds checking in the ParseBqrLinkQualityEvt function. Additionally, network administrators should consider implementing Bluetooth access controls and monitoring for anomalous Bluetooth Quality Report data patterns that could indicate exploitation attempts. The vulnerability serves as a reminder of the importance of robust input validation and bounds checking in system-level code, particularly within security-sensitive components that handle external data inputs. Organizations should also conduct thorough security assessments of their Bluetooth-enabled devices to identify any potential exploitation vectors that could leverage similar vulnerabilities in other system components.