CVE-2025-51630
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on TOTOLINK N350RT routers by exploiting a buffer overflow in the ePort parameter. Attackers can gain full control of affected devices, potentially compromising entire networks. Only users of specific TOTOLINK N350RT firmware versions are affected.
💻 Affected Systems
- TOTOLINK N350RT
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover leading to persistent backdoor installation, network traffic interception, lateral movement to other devices, and participation in botnets.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation is implemented.
🎯 Exploit Status
Public proof-of-concept available on GitHub. Exploitation requires network access to the router's web interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: Yes
Instructions:
1. Check TOTOLINK website for firmware updates. 2. Download latest firmware. 3. Access router web interface. 4. Navigate to firmware upgrade section. 5. Upload new firmware file. 6. Wait for reboot.
🔧 Temporary Workarounds
Restrict Network Access
linuxBlock external access to router management interface using firewall rules.
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Disable Remote Management
allTurn off remote administration features in router settings.
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict access controls
- Implement network monitoring for suspicious traffic to/from router management interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at System Status > Firmware VersionCheck Version:
curl -s http://router-ip/status.cgi | grep firmwareVerify Fix Applied:
Verify firmware version has changed from V9.3.5u.6139_B20201216📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to setIpPortFilterRules endpoint
- Multiple failed login attempts followed by successful access
Network Indicators:
- Unusual outbound connections from router
- Traffic to known malicious IPs from router
SIEM Query:
source="router.log" AND (uri="/cgi-bin/setIpPortFilterRules" OR "ePort=" AND content_length>100)