CVE-2024-20139
📋 TL;DR
This CVE describes a Bluetooth firmware vulnerability in MediaTek chipsets where improper handling of exceptional conditions can cause a firmware assertion (crash). This leads to local denial of service without requiring user interaction or elevated privileges. Devices using affected MediaTek Bluetooth chipsets are vulnerable.
💻 Affected Systems
- MediaTek Bluetooth chipsets
📦 What is this software?
Android by Google
Android by Google
Android by Google
Openwrt by Openwrt
Yocto by Linuxfoundation
Yocto by Linuxfoundation
Yocto by Linuxfoundation
⚠️ Risk & Real-World Impact
Worst Case
Permanent Bluetooth functionality loss requiring device restart or factory reset, potentially affecting all Bluetooth-dependent services on the device.
Likely Case
Temporary Bluetooth service disruption affecting wireless peripherals, audio devices, and file transfers until system restart.
If Mitigated
Minimal impact with proper network segmentation and Bluetooth usage policies limiting attack surface.
🎯 Exploit Status
No authentication or user interaction required. Exploitation requires Bluetooth proximity and ability to send malformed packets.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware patch ID: ALPS09001270
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/December-2024
Restart Required: Yes
Instructions:
1. Contact device manufacturer for firmware updates. 2. Apply MediaTek-provided firmware patch ALPS09001270. 3. Restart device to load patched firmware.
🔧 Temporary Workarounds
Disable Bluetooth
allTurn off Bluetooth functionality to prevent exploitation
# Android: adb shell settings put global bluetooth_on 0
# Linux: sudo systemctl stop bluetooth
# Linux: sudo rfkill block bluetooth
Limit Bluetooth Visibility
allSet Bluetooth to non-discoverable mode to reduce attack surface
# Android: adb shell settings put global bluetooth_discoverability 0
# Linux Bluetoothctl: set Discoverable off
🧯 If You Can't Patch
- Implement network segmentation to isolate Bluetooth devices from untrusted networks
- Deploy physical security controls to limit Bluetooth range and unauthorized device proximity
🔍 How to Verify
Check if Vulnerable:
Check device specifications for MediaTek Bluetooth chipset and firmware version against vendor advisoryCheck Version:
# Check Bluetooth firmware: dmesg | grep -i bluetooth | grep -i firmwareVerify Fix Applied:
Verify firmware version includes patch ALPS09001270 via manufacturer tools or system logs📡 Detection & Monitoring
Log Indicators:
- Bluetooth firmware crash/assertion logs
- Bluetooth service restart events
- Unexpected Bluetooth disconnections
Network Indicators:
- Unusual Bluetooth packet patterns from unknown MAC addresses
- Multiple Bluetooth connection attempts in short timeframe
SIEM Query:
source="bluetooth" AND (event="crash" OR event="assert" OR event="firmware_failure")