CVE-2022-21767
📋 TL;DR
CVE-2022-21767 is a Bluetooth stack vulnerability in MediaTek chipsets that allows local privilege escalation without user interaction. An attacker can exploit an out-of-bounds write to gain elevated privileges on affected devices. This affects Android devices using vulnerable MediaTek Bluetooth components.
💻 Affected Systems
- MediaTek Bluetooth chipsets in Android devices
📦 What is this software?
Android by Google
Android by Google
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attacker to execute arbitrary code with system privileges, install persistent malware, or access sensitive data.
Likely Case
Local privilege escalation allowing malware or malicious apps to gain higher permissions than originally granted.
If Mitigated
Limited impact if Bluetooth is disabled or device is fully patched with the latest firmware.
🎯 Exploit Status
Exploitation requires Bluetooth proximity but no user interaction. Technical details suggest specialized knowledge needed for reliable exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware with patch ID ALPS06784430
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/July-2022
Restart Required: Yes
Instructions:
1. Check device manufacturer for security updates. 2. Apply Android security patch from July 2022 or later. 3. Reboot device after update. 4. Verify Bluetooth firmware version includes ALPS06784430 patch.
🔧 Temporary Workarounds
Disable Bluetooth
androidTurn off Bluetooth when not in use to prevent exploitation
adb shell settings put global bluetooth_on 0
Settings > Connected devices > Connection preferences > Bluetooth > Turn off
Restrict Bluetooth visibility
androidSet Bluetooth to non-discoverable mode to reduce attack surface
adb shell am start -a android.settings.BLUETOOTH_SETTINGS
Settings > Connected devices > Connection preferences > Bluetooth > Device name > Turn off visibility
🧯 If You Can't Patch
- Disable Bluetooth completely when not actively pairing devices
- Implement network segmentation to isolate vulnerable devices from critical systems
🔍 How to Verify
Check if Vulnerable:
Check device security patch level: Settings > About phone > Android version > Security patch level. If before July 2022, likely vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify security patch level is July 2022 or later and check with manufacturer for specific MediaTek patch confirmation.📡 Detection & Monitoring
Log Indicators:
- Unusual Bluetooth stack crashes
- Privilege escalation attempts in system logs
- Suspicious Bluetooth pairing requests
Network Indicators:
- Abnormal Bluetooth traffic patterns
- Multiple failed pairing attempts from unknown devices
SIEM Query:
source="android_system" AND ("bluetooth" AND ("crash" OR "privilege" OR "escalation"))