CVE-2025-5630
📋 TL;DR
This critical vulnerability in D-Link DIR-816 routers allows remote attackers to execute arbitrary code via a stack-based buffer overflow in the web interface's form2lansetup.cgi endpoint. Attackers can exploit this without authentication to potentially take full control of affected devices. Only users of unsupported D-Link DIR-816 routers with specific firmware versions are affected.
💻 Affected Systems
- D-Link DIR-816
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing persistent backdoor installation, network traffic interception, lateral movement to internal networks, and botnet recruitment.
Likely Case
Remote code execution leading to device takeover, credential theft, and use as pivot point for internal network attacks.
If Mitigated
Limited impact if device is isolated in separate VLAN with strict network segmentation and egress filtering.
🎯 Exploit Status
Public exploit code available on GitHub. Remote exploitation requires no authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: None
Vendor Advisory: https://www.dlink.com/
Restart Required: No
Instructions:
No official patch available. Product is end-of-life. Replace with supported hardware.
🔧 Temporary Workarounds
Disable web interface access
linuxBlock external access to router web interface
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Network segmentation
allIsolate vulnerable routers in separate VLAN
🧯 If You Can't Patch
- Immediately replace affected routers with supported hardware
- Implement strict network segmentation and firewall rules to limit router access
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at 192.168.0.1 or using curl: curl -s http://192.168.0.1/ | grep -i firmwareCheck Version:
curl -s http://192.168.0.1/ | grep -i 'firmware.*1.10CNB05'Verify Fix Applied:
Verify router has been replaced or web interface is inaccessible from untrusted networks📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/form2lansetup.cgi with long ip parameter
- Unusual process execution in router logs
Network Indicators:
- HTTP POST requests to form2lansetup.cgi with oversized payloads
- Unusual outbound connections from router
SIEM Query:
source="router_logs" AND uri="/goform/form2lansetup.cgi" AND content_length>1000