← Port Encyclopedia
857
Port-857
TCP
System Low Risk
Reserved or unassigned port 857 — may appear in network scans as open, closed, or filtered

🔍 How to Scan Port 857

nmap -sV -p 857 target
nmap -sV -sC --script=banner -p 857 target
nc -zv target 857

🛡️ Security Considerations

  • Scan port 857 with nmap -sV to identify the exact service and version
  • If Port-857 is not needed, close or firewall this port immediately
  • Check for default credentials if a management interface runs on this port
  • Use searchsploit port-857 to find known exploits
  • Monitor traffic on port 857 with Wireshark or tcpdump for anomalies
  • Ensure the service is patched to the latest version to prevent known CVE exploitation