CVE-2021-0918
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on Android devices via Bluetooth without user interaction. It affects Android 12 devices due to a missing bounds check in the Bluetooth GATT notification processing. Attackers within Bluetooth range can potentially take full control of vulnerable devices.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, data theft, surveillance, or device bricking.
Likely Case
Remote code execution allowing installation of malware, data exfiltration, or device control.
If Mitigated
No impact if patched or Bluetooth disabled; limited impact if Bluetooth range restrictions apply.
🎯 Exploit Status
Exploitation requires Bluetooth proximity and knowledge of the vulnerability, but no authentication or user interaction.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android Security Patch Level 2021-11-01 or later
Vendor Advisory: https://source.android.com/security/bulletin/2021-11-01
Restart Required: Yes
Instructions:
1. Check for Android system updates in Settings > System > System update. 2. Install the November 2021 security patch or later. 3. Restart the device after installation.
🔧 Temporary Workarounds
Disable Bluetooth
androidTurn off Bluetooth to prevent exploitation via this vector.
Settings > Connected devices > Connection preferences > Bluetooth > Toggle off
Restrict Bluetooth visibility
androidSet Bluetooth to non-discoverable mode to reduce attack surface.
Settings > Connected devices > Connection preferences > Bluetooth > Device name > Turn off 'Make device discoverable'
🧯 If You Can't Patch
- Disable Bluetooth when not in use, especially in public or untrusted environments.
- Use Bluetooth only with trusted devices and avoid pairing with unknown devices.
🔍 How to Verify
Check if Vulnerable:
Check Android version and security patch level: Settings > About phone > Android version and Security patch level.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify security patch level is 2021-11-01 or later in Settings > About phone > Security patch level.📡 Detection & Monitoring
Log Indicators:
- Unusual Bluetooth connection attempts, crashes in Bluetooth stack (logcat entries with gatt_process_notification or BluetoothService)
Network Indicators:
- Suspicious Bluetooth traffic patterns, unexpected device pairing
SIEM Query:
Not typically applicable for mobile device Bluetooth attacks; monitor for Bluetooth stack crashes or anomalies.