CVE-2023-20985 in Android
Summary
by MITRE • 03/24/2023
In BTA_GATTS_HandleValueIndication of bta_gatts_api.cc, there is a possible out of bounds write due to improper input validation. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-13Android ID: A-245915315
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Analysis
by VulDB Data Team • 09/07/2025
The vulnerability identified as CVE-2023-20985 resides within the Bluetooth GATT server implementation of Android 13, specifically in the BTA_GATTS_HandleValueIndication function located in bta_gatts_api.cc. This flaw represents a critical security weakness that allows for local privilege escalation without requiring any additional execution privileges or user interaction for exploitation. The vulnerability manifests as an out-of-bounds write condition that occurs due to inadequate input validation mechanisms within the Bluetooth GATT server handling code.
The technical root cause of this vulnerability stems from improper validation of input parameters when processing GATT handle value indication requests. When the system receives a malformed or oversized data payload during Bluetooth GATT operations, the BTA_GATTS_HandleValueIndication function fails to properly bounds-check the incoming data before writing it to memory locations. This oversight creates a scenario where maliciously crafted Bluetooth GATT packets can overwrite adjacent memory regions, potentially corrupting critical system data structures or executing arbitrary code with elevated privileges. The vulnerability falls under CWE-787, which specifically addresses out-of-bounds write conditions that can lead to privilege escalation and system compromise.
From an operational perspective, this vulnerability presents a significant risk to Android 13 devices since it enables local privilege escalation without requiring user interaction or additional execution privileges. An attacker who gains access to the device's Bluetooth capabilities could exploit this flaw to elevate their privileges and gain access to sensitive system resources. The lack of user interaction requirements makes this vulnerability particularly dangerous as it can be exploited automatically when Bluetooth services are active. The attack surface is broad since Bluetooth functionality is commonly enabled on Android devices for various legitimate purposes including pairing with accessories, IoT devices, and other Bluetooth-enabled systems.
The exploitation of this vulnerability aligns with ATT&CK technique T1068, which covers 'Local Privilege Escalation' and specifically targets weaknesses in system-level security controls. This vulnerability demonstrates how Bluetooth protocol implementations can serve as attack vectors for privilege escalation, particularly when memory safety mechanisms are insufficient. The Android security model relies heavily on proper input validation and memory bounds checking to prevent such scenarios, but this flaw indicates a gap in the validation process that allows attackers to bypass these protective measures. Organizations should consider this vulnerability as part of their broader security posture assessment, particularly for devices that maintain active Bluetooth connectivity or are used in environments where Bluetooth exposure is common.
Mitigation strategies for this vulnerability should include immediate deployment of security patches provided by Google for Android 13 devices. System administrators should ensure that all affected devices receive the latest security updates as soon as they become available. Additionally, organizations should consider implementing Bluetooth access controls and monitoring for unusual Bluetooth activity patterns that might indicate exploitation attempts. Network segmentation and access controls can help limit the potential impact of exploitation, while regular security assessments should include evaluation of Bluetooth protocol implementations to identify similar vulnerabilities. The vulnerability serves as a reminder of the importance of robust input validation in system-level code and the critical need for comprehensive security testing of all Bluetooth protocol implementations within mobile operating systems.