CVE-2025-20682
📋 TL;DR
This vulnerability in MediaTek wlan AP driver allows local attackers to write beyond allocated memory boundaries, potentially gaining elevated system privileges. It affects devices using 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 across 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 local code execution required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: WCNCR00416937
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 WCNCR00416937
3. Reboot device after patch installation
4. Verify patch application through version checking
🔧 Temporary Workarounds
Disable vulnerable driver module
linuxTemporarily disable the affected wlan AP driver module to prevent exploitation
rmmod mt_wlan_ap
echo 'blacklist mt_wlan_ap' >> /etc/modprobe.d/blacklist.conf
Restrict driver permissions
linuxLimit access to the driver module to prevent unauthorized execution
chmod 600 /sys/module/mt_wlan_ap
setfacl -m u:root:rw- /sys/module/mt_wlan_ap
🧯 If You Can't Patch
- Implement strict access controls to limit local user privileges
- Monitor for suspicious driver module loading or memory corruption attempts
🔍 How to Verify
Check if Vulnerable:
Check if MediaTek wlan AP driver is loaded: lsmod | grep mt_wlan_apCheck Version:
dmesg | grep -i mediatek || cat /proc/versionVerify Fix Applied:
Verify patch WCNCR00416937 is applied through manufacturer firmware version or driver version check📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages related to wlan driver
- Out of bounds memory access errors in system logs
- Unexpected driver module loading
Network Indicators:
- Unusual wireless interface behavior
- Suspicious local privilege escalation attempts
SIEM Query:
source="kernel" AND ("out of bounds" OR "wlan" OR "mediatek")