CVE-2025-5671
📋 TL;DR
A critical buffer overflow vulnerability in TOTOLINK N302R Plus routers allows remote attackers to execute arbitrary code by sending specially crafted HTTP POST requests to the /boafrm/formPortFw endpoint. This affects all versions up to 3.4.0-B20201028. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- TOTOLINK N302R Plus
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistent backdoor installation, lateral movement to internal networks, and botnet recruitment.
Likely Case
Remote code execution resulting in device takeover, credential theft, DNS hijacking, and participation in DDoS attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict ingress filtering and network segmentation.
🎯 Exploit Status
Public exploit code available on GitHub, requires sending crafted HTTP POST with overflow in service_type parameter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.totolink.net/
Restart Required: Yes
Instructions:
1. Check vendor website for firmware updates. 2. Download latest firmware. 3. Log into router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable Web Management Interface
allPrevent HTTP access to vulnerable endpoint
Login to router admin → System Tools → Management → Disable Remote Management
Network Access Control
linuxRestrict access to router management interface
iptables -A INPUT -p tcp --dport 80 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict firewall rules
- Implement network-based intrusion detection for exploit patterns
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface or via command: curl -s http://router-ip/ | grep -i versionCheck Version:
curl -s http://router-ip/ | grep -i 'firmware\|version'Verify Fix Applied:
Verify firmware version is newer than 3.4.0-B20201028📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /boafrm/formPortFw with long service_type parameter
- Router crash/reboot logs
Network Indicators:
- HTTP traffic to router port 80 with POST to vulnerable endpoint
- Unusual outbound connections from router
SIEM Query:
source="router_logs" AND url="/boafrm/formPortFw" AND method="POST" AND (content_length>100 OR contains(param,"service_type"))