CVE-2025-20676
📋 TL;DR
This vulnerability in MediaTek's WLAN STA driver allows local attackers with user privileges to trigger a system crash through an uncaught exception, causing denial of service without requiring user interaction. It affects devices using MediaTek wireless chipsets with vulnerable driver versions.
💻 Affected Systems
- MediaTek WLAN STA driver
📦 What is this software?
Nbiot Sdk by Mediatek
⚠️ Risk & Real-World Impact
Worst Case
Complete system crash requiring hard reboot, potentially causing data loss or corruption in active processes.
Likely Case
Local denial of service affecting wireless connectivity and potentially requiring system restart.
If Mitigated
Minimal impact if patched or if system has proper privilege separation preventing user access to driver interfaces.
🎯 Exploit Status
Exploitation requires user privileges but no special interaction. Likely involves triggering specific driver states to cause the uncaught exception.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patch ID: WCNCR00412240
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/June-2025
Restart Required: Yes
Instructions:
1. Check device manufacturer for firmware updates. 2. Apply MediaTek-provided patch WCNCR00412240. 3. Reboot device to load patched driver.
🔧 Temporary Workarounds
Restrict user access to wireless driver interfaces
linuxLimit user permissions to prevent triggering the vulnerable driver code path
# Review and tighten permissions on /sys/class/net/wlan* and related interfaces
Disable vulnerable wireless features if unused
allTurn off specific WLAN features that might trigger the exception
# Consult device-specific documentation for disabling advanced WLAN features
🧯 If You Can't Patch
- Implement strict user privilege controls to limit who can execute code on affected devices
- Monitor system logs for crash events related to wlan driver and investigate any suspicious user activity
🔍 How to Verify
Check if Vulnerable:
Check if device uses MediaTek wireless chipset and driver version predates patch WCNCR00412240Check Version:
# Check wireless driver version: dmesg | grep -i mediatek || lsmod | grep -i mtkVerify Fix Applied:
Verify patch WCNCR00412240 is applied in system firmware/driver version📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages mentioning wlan driver
- System crash logs with stack traces pointing to MediaTek wireless modules
- Unexpected system reboots with wireless activity
Network Indicators:
- Sudden loss of wireless connectivity on affected devices
SIEM Query:
source="kernel" AND ("panic" OR "Oops") AND ("wlan" OR "mediatek" OR "mtk")