CVE-2025-20718
📋 TL;DR
This vulnerability in MediaTek WLAN AP drivers allows local attackers to write beyond allocated memory boundaries, potentially gaining elevated system privileges. It affects devices using vulnerable MediaTek wireless chipsets, requiring only user-level execution privileges with no user interaction needed for exploitation.
💻 Affected Systems
- MediaTek WLAN AP driver
📦 What is this software?
Openwrt by Openwrt
Openwrt by Openwrt
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with root/kernel-level access, allowing installation of persistent malware, data theft, and lateral movement within the network.
Likely Case
Local privilege escalation to gain administrative control over affected devices, enabling further attacks on the system and network.
If Mitigated
Limited impact if proper privilege separation and driver sandboxing are implemented, though kernel-level access remains possible.
🎯 Exploit Status
Requires local access and user execution privileges. No authentication bypass needed but attacker must have initial access to the device.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patch ID: WCNCR00419945
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/October-2025
Restart Required: Yes
Instructions:
1. Check device manufacturer for firmware updates. 2. Apply MediaTek patch WCNCR00419945. 3. Reboot device after patch installation. 4. Verify patch application through version checking.
🔧 Temporary Workarounds
Disable WLAN interface
linuxTemporarily disable wireless functionality to prevent driver exploitation
ip link set wlan0 down
rfkill block wifi
Restrict driver module loading
linuxPrevent loading of vulnerable WLAN driver module
echo 'blacklist mt_wlan' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Implement strict access controls to limit local user privileges
- Deploy endpoint detection and response (EDR) solutions to monitor for privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check driver version and compare against patched versions in MediaTek advisoryCheck Version:
dmesg | grep -i 'wlan\|mediatek' or check /sys/module/ for driver informationVerify Fix Applied:
Verify patch WCNCR00419945 is applied through system logs or driver version checks📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- Driver crash logs
- Unexpected privilege escalation events
Network Indicators:
- Unusual outbound connections from affected devices
- Anomalous network scanning behavior
SIEM Query:
source="kernel" AND ("wlan" OR "mediatek") AND ("panic" OR "oops" OR "segfault")