CVE-2025-20688
📋 TL;DR
This vulnerability in MediaTek wlan AP driver allows local attackers to read memory beyond intended boundaries, potentially exposing sensitive information. It affects devices with MediaTek wireless chipsets and requires local access with user privileges. No user interaction is 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
Sensitive kernel memory disclosure including passwords, encryption keys, or other system secrets could be extracted by a local attacker.
Likely Case
Limited information disclosure from driver memory space, potentially exposing network configuration data or adjacent process memory.
If Mitigated
Minimal impact with proper access controls and isolation preventing unauthorized local access to affected systems.
🎯 Exploit Status
Requires local user access and knowledge of driver memory layout. No public exploit code known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patch ID: WCNCR00418047
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 WCNCR00418047. 3. Reboot device to load patched driver.
🔧 Temporary Workarounds
Restrict local user access
allLimit local shell access to trusted users only on affected devices
Disable vulnerable driver module
linuxUnload or blacklist the affected wlan AP driver if wireless functionality can be disabled
rmmod mtk_wlan_ap_driver
echo 'blacklist mtk_wlan_ap_driver' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Implement strict access controls to prevent untrusted local users from accessing affected systems
- Monitor for unusual local privilege escalation attempts or memory access patterns
🔍 How to Verify
Check if Vulnerable:
Check driver version: lsmod | grep mtk_wlan_ap_driver and compare against patched versions from vendorCheck Version:
dmesg | grep -i mediatek && lsmod | grep -i mtkVerify Fix Applied:
Verify patch is applied by checking driver version or confirming patch ID WCNCR00418047 in system logs📡 Detection & Monitoring
Log Indicators:
- Kernel logs showing out-of-bounds memory access
- Driver crash or unusual memory access patterns in system logs
Network Indicators:
- No network indicators - local exploit only
SIEM Query:
source="kernel" AND "out of bounds" AND "wlan" OR source="kernel" AND "mediatek" AND "segmentation fault"