← Port Encyclopedia
23
Telnet
TCP
Remote Access
Critical Risk
Telnet — unencrypted remote access, all data including passwords sent in cleartext
🔍 How to Scan Port 23
nmap -sV -p 23 target
nmap -sV -sC --script=banner -p 23 target
nc -zv target 23
🛡️ Security Considerations
- Scan port 23 with
nmap -sVto identify the exact service and version - If Telnet is not needed, close or firewall this port immediately
- Check for default credentials if a management interface runs on this port
- Use
searchsploit telnetto find known exploits - Monitor traffic on port 23 with Wireshark or tcpdump for anomalies
- Ensure the service is patched to the latest version to prevent known CVE exploitation