CVE-2025-20680
📋 TL;DR
This CVE describes a critical Bluetooth driver vulnerability allowing local privilege escalation without user interaction. An attacker with user-level access can exploit an out-of-bounds write to gain elevated system privileges. This affects devices using MediaTek Bluetooth components.
💻 Affected Systems
- MediaTek Bluetooth drivers/chipsets
📦 What is this software?
Nbiot Sdk by Mediatek
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attacker to install persistent malware, access sensitive data, and pivot to other systems.
Likely Case
Local privilege escalation enabling installation of additional malware, credential theft, and persistence mechanisms.
If Mitigated
Limited impact if Bluetooth is disabled or strict access controls prevent local user execution.
🎯 Exploit Status
Requires local user execution privileges but no user interaction; exploit development likely requires driver-specific knowledge
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: WCNCR00418044
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/July-2025
Restart Required: Yes
Instructions:
1. Check device manufacturer for firmware updates. 2. Apply MediaTek patch WCNCR00418044. 3. Reboot device. 4. Verify Bluetooth functionality.
🔧 Temporary Workarounds
Disable Bluetooth
linuxCompletely disable Bluetooth functionality to prevent exploitation
sudo systemctl disable bluetooth
sudo systemctl stop bluetooth
Restrict Bluetooth permissions
linuxLimit which users can access Bluetooth services
sudo chmod 750 /usr/lib/bluetooth/
sudo setfacl -m u:root:rwx /sys/class/bluetooth/
🧯 If You Can't Patch
- Implement strict user access controls and privilege separation
- Deploy endpoint detection and response (EDR) to monitor for privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check Bluetooth driver version: lsmod | grep btmtk or dmesg | grep -i mediatekCheck Version:
uname -r && modinfo btmtk | grep versionVerify Fix Applied:
Verify patch applied: check system logs for WCNCR00418044 or updated driver version📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- Bluetooth driver crash logs
- Unexpected privilege escalation events
Network Indicators:
- Unusual Bluetooth pairing attempts
- Abnormal Bluetooth service behavior
SIEM Query:
source="kernel" AND "bluetooth" AND ("panic" OR "oops" OR "segfault")