← 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 -sV to 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 telnet to 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

🔗 Related Remote Access Ports

Port 22
SSH
Port 512
rexec
Port 513
rlogin
Port 543
Klogin
Port 544
Kshell
Port 1494
Citrix-ICA
Port 1500
RDP-Alt
Port 2222
SSH-Alt
Port 2323
Telnet-Alt
Port 2598
Citrix-CGP
Port 3283
Apple-Remote
Port 3389
RDP

📍 Nearby Ports

Port 18
Port-18
Port 19
Chargen
Port 20
FTP-Data
Port 21
FTP
Port 22
SSH
Port 24
Port-24
Port 25
SMTP
Port 26
RSFTP
Port 27
Port-27
Port 28
Port-28
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