CVE-2025-45845
📋 TL;DR
This vulnerability allows authenticated attackers to execute arbitrary code on TOTOLINK NR1800X routers via a stack overflow in the setWiFiEasyGuestCfg function. Attackers with valid credentials can exploit this to gain full control of affected devices. Only TOTOLINK NR1800X routers running specific vulnerable firmware versions are affected.
💻 Affected Systems
- TOTOLINK NR1800X
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, lateral movement to other devices, and botnet recruitment.
Likely Case
Local network compromise allowing attacker to reconfigure router settings, intercept traffic, and potentially pivot to other devices on the network.
If Mitigated
Limited impact if strong authentication is enforced and network segmentation isolates the router from critical systems.
🎯 Exploit Status
Exploit code is publicly available in GitHub repositories. Requires valid credentials but exploitation is straightforward once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.totolink.net
Restart Required: Yes
Instructions:
1. Check TOTOLINK website for firmware updates. 2. Download latest firmware for NR1800X. 3. Log into router web interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload new firmware file. 6. Wait for automatic reboot.
🔧 Temporary Workarounds
Disable Guest WiFi
allDisable the 5GHz guest WiFi network to prevent access to vulnerable function
Change Admin Credentials
allUse strong, unique passwords for router administration
🧯 If You Can't Patch
- Isolate router on separate VLAN away from critical systems
- Implement network monitoring for unusual traffic patterns from router
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under System Tools > Firmware UpgradeCheck Version:
Login to router web interface and navigate to System Status or Firmware Upgrade pageVerify Fix Applied:
Verify firmware version has been updated to a version newer than V9.1.0u.6681_B20230703📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by successful login
- Unusual configuration changes to WiFi settings
- Large payloads sent to setWiFiEasyGuestCfg endpoint
Network Indicators:
- Unusual outbound connections from router
- Traffic patterns suggesting command and control communication
- Port scanning originating from router
SIEM Query:
source="router_logs" AND (event="authentication_success" AND user="admin") AND (event="configuration_change" AND setting="wifi_guest")