← Port Encyclopedia
137
NetBIOS-NS
UDP
Windows
High Risk
NetBIOS Name Service — Windows name resolution, null session enumeration
🔍 How to Scan Port 137
nmap -sV -p 137 target
nmap -sV -sC --script=banner -p 137 target
nc -zv target 137
🛡️ Security Considerations
- Scan port 137 with
nmap -sVto identify the exact service and version - If NetBIOS-NS is not needed, close or firewall this port immediately
- Check for default credentials if a management interface runs on this port
- Use
searchsploit netbios-nsto find known exploits - Monitor traffic on port 137 with Wireshark or tcpdump for anomalies
- Ensure the service is patched to the latest version to prevent known CVE exploitation