CVE-2025-20742
📋 TL;DR
This CVE describes a critical vulnerability in MediaTek WLAN AP drivers where an incorrect bounds check allows out-of-bounds write. Attackers within wireless range can exploit this to gain elevated privileges without user interaction. This affects devices using vulnerable MediaTek wireless chipsets.
💻 Affected Systems
- MediaTek WLAN AP driver
📦 What is this software?
Openwrt by Openwrt
Openwrt by Openwrt
⚠️ Risk & Real-World Impact
Worst Case
Remote attacker gains full system control over affected devices, potentially installing persistent malware, exfiltrating data, or using device as pivot point in network.
Likely Case
Attacker within wireless range gains elevated privileges on vulnerable device, enabling further network reconnaissance, lateral movement, or data theft.
If Mitigated
With proper network segmentation and wireless security controls, impact limited to isolated wireless segment with minimal critical assets.
🎯 Exploit Status
Exploitation requires proximity/adjacent network access but no authentication or user interaction
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: WCNCR00432680
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/November-2025
Restart Required: Yes
Instructions:
1. Contact device manufacturer for firmware updates. 2. Apply patch WCNCR00432680. 3. Reboot affected devices. 4. Verify patch installation.
🔧 Temporary Workarounds
Disable vulnerable WLAN interfaces
linuxTemporarily disable wireless interfaces on affected devices
ip link set wlan0 down
Restrict wireless network access
allImplement strict wireless access controls and network segmentation
🧯 If You Can't Patch
- Isolate affected devices on separate VLAN with strict firewall rules
- Implement wireless intrusion detection/prevention systems to monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check device specifications for MediaTek wireless chipset and firmware version; consult manufacturer for vulnerability statusCheck Version:
Manufacturer-specific command; typically in device settings or via 'dmesg | grep -i mediatek' on Linux systemsVerify Fix Applied:
Verify patch WCNCR00432680 is installed via firmware version check📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- Driver crash reports
- Unusual privilege escalation events
Network Indicators:
- Unusual wireless traffic patterns
- Suspicious MAC addresses attempting driver-level communication
SIEM Query:
source="kernel" AND ("panic" OR "oops") AND "wlan" OR source="wireless" AND event_type="anomaly"