CVE-2025-20729
📋 TL;DR
This CVE describes an out-of-bounds write vulnerability in MediaTek wlan AP drivers due to incorrect bounds checking. It allows local privilege escalation from System to higher privileges without user interaction. Affects devices using vulnerable MediaTek wireless chipset drivers.
💻 Affected Systems
- MediaTek wlan AP drivers
📦 What is this software?
Openwrt by Openwrt
Openwrt by Openwrt
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with kernel-level code execution, allowing attackers to install persistent malware, steal sensitive data, or disable security controls.
Likely Case
Local privilege escalation enabling attackers to gain elevated permissions, potentially leading to lateral movement within the network or persistence mechanisms.
If Mitigated
Limited impact if proper privilege separation and driver sandboxing are implemented, though kernel-level vulnerabilities remain serious.
🎯 Exploit Status
Requires System privilege first, making it a secondary exploitation vector rather than initial access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patch ID: WCNCR00441512
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/November-2025
Restart Required: Yes
Instructions:
1. Check device manufacturer for firmware updates. 2. Apply MediaTek patch WCNCR00441512. 3. Reboot device to load patched driver.
🔧 Temporary Workarounds
Disable vulnerable driver module
linuxTemporarily disable the affected wlan AP driver module if wireless functionality can be sacrificed
modprobe -r mtk_wlan_ap_driver
echo 'blacklist mtk_wlan_ap_driver' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Implement strict privilege separation to limit System account access
- Monitor for suspicious driver loading or privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check driver version: lsmod | grep mtk_wlan_ap && check if patch WCNCR00441512 is appliedCheck Version:
dmesg | grep -i mtk_wlan_ap || lsmod | grep mtk_wlan_apVerify Fix Applied:
Verify patch installation via manufacturer firmware version or driver version check📡 Detection & Monitoring
Log Indicators:
- Kernel logs showing driver crashes or out-of-bounds memory access
- Unexpected driver module loading
Network Indicators:
- None - local exploitation only
SIEM Query:
EventID=System AND Source=Kernel AND (Message contains 'out of bounds' OR 'driver crash' OR 'mtk_wlan_ap')