CVE-2025-22435: Google Android Privilege Escalation Flaw

CVE-2025-22435 Overview

A critical type confusion vulnerability has been identified in the Android Bluetooth stack, specifically in the avdt_msg_ind function within avdt_msg.cc. This memory corruption flaw affects the Audio/Video Distribution Transport Protocol (AVDT) message handling component, enabling paired device privilege escalation without requiring any user interaction or additional execution privileges.

Critical Impact

This vulnerability allows a paired Bluetooth device to escalate privileges on the target Android device through memory corruption, potentially gaining unauthorized control over sensitive system functions without user awareness.

Affected Products

• Google Android 13.0
• Google Android 14.0
• Google Android 15.0

Discovery Timeline

• 2025-04-01 - Google releases security patch via Android Security Bulletin April 2025
• 2025-09-02 - CVE-2025-22435 published to NVD
• 2025-09-04 - Last updated in NVD database

Technical Details for CVE-2025-22435

Vulnerability Analysis

The vulnerability resides in the AVDT (Audio/Video Distribution Transport Protocol) message indication handler within Android's Bluetooth stack. AVDT is a critical protocol used for streaming audio and video data between Bluetooth devices, making this vulnerability particularly concerning for devices using Bluetooth audio functionality.

The type confusion flaw (CWE-843) occurs when the avdt_msg_ind function improperly handles message types, causing the system to interpret data structures incorrectly. When a malicious paired device sends specially crafted AVDT messages, the parser misinterprets the type of incoming data, leading to memory corruption.

This vulnerability is especially dangerous because it requires no user interaction for exploitation. Once a device is paired, an attacker can leverage the established trust relationship to trigger the vulnerability remotely over the network. The attack does not require any additional execution privileges on the attacker's side, significantly lowering the barrier to exploitation.

Root Cause

The root cause is a type confusion error in the AVDT message parsing logic within avdt_msg.cc. The function avdt_msg_ind fails to properly validate or distinguish between different message types before processing them. This allows an attacker to supply data that is interpreted as a different type than intended, causing the Bluetooth stack to access memory regions with incorrect assumptions about the data structure layout.

Type confusion vulnerabilities in low-level protocol handlers like Bluetooth are particularly severe because they operate with elevated system privileges and handle data from external, potentially untrusted sources.

Attack Vector

The attack exploits the Bluetooth pairing trust model. An attacker with a previously paired device—or one that has compromised the pairing process—can send malformed AVDT messages to the target Android device over a network connection. The vulnerability in avdt_msg_ind processes these messages without proper type validation, resulting in:

1. Memory corruption within the Bluetooth process context
2. Potential code execution with Bluetooth service privileges
3. Privilege escalation on the paired device

Since no user interaction is required and the attack occurs over the network between paired devices, exploitation can be completely silent to the device user.

Detection Methods for CVE-2025-22435

Indicators of Compromise

• Unusual Bluetooth service crashes or restarts logged in system logs
• Unexpected AVDT protocol messages from paired devices captured in Bluetooth HCI logs
• Abnormal memory allocation patterns in the com.android.bluetooth process
• Suspicious privilege escalation attempts originating from Bluetooth system components

Detection Strategies

• Monitor Android system logs for Bluetooth stack crashes, particularly those referencing avdt_msg.cc or AVDT-related functions
• Implement Bluetooth HCI log analysis to detect malformed or anomalous AVDT message sequences
• Deploy endpoint detection solutions capable of monitoring Android system service behavior for signs of memory corruption exploitation
• Review paired Bluetooth device lists for unknown or suspicious entries that could be used as attack vectors

Monitoring Recommendations

• Enable verbose Bluetooth debugging logs during security investigations to capture AVDT message traffic
• Configure SentinelOne Mobile Threat Defense to monitor for Bluetooth service anomalies and privilege escalation attempts
• Establish baseline Bluetooth activity patterns to identify deviations indicative of exploitation attempts
• Monitor for unauthorized paired device connections, especially from MAC addresses not associated with legitimate user devices

How to Mitigate CVE-2025-22435

Immediate Actions Required

• Apply the April 2025 Android Security Patch immediately to all affected devices running Android 13.0, 14.0, and 15.0
• Review and remove any unnecessary or unknown paired Bluetooth devices from all Android devices
• Disable Bluetooth functionality on critical devices until patches can be applied
• Implement network segmentation to limit Bluetooth attack surface in enterprise environments

Patch Information

Google has addressed this vulnerability in the Android Security Bulletin April 2025. The fix is available through the Android Bluetooth Module Update with commit hash efa5f4ef386a8947f4777840c5cefff389740e86.

Organizations should ensure all Android devices are updated to the 2025-04-01 security patch level or later. The patch corrects the type handling logic in avdt_msg_ind to properly validate message types before processing, preventing the memory corruption condition.

Workarounds

• Disable Bluetooth on devices where the patch cannot be immediately applied
• Remove all paired Bluetooth devices and re-pair only essential, trusted devices after patching
• Implement Mobile Device Management (MDM) policies to restrict Bluetooth pairing capabilities on enterprise devices
• Use Bluetooth Low Energy (BLE) only mode where supported, as this may reduce AVDT protocol exposure

# Disable Bluetooth via ADB for unpatched devices (requires developer mode)
adb shell settings put global bluetooth_on 0
adb shell svc bluetooth disable