Port Scanning & Security Audits

A port scanner helps discover services running on a server. Attackers scan for open ports to identify potentially vulnerable services (like an outdated FTP server or unsecured MySQL database) to exploit.

Risky Ports to Watch

• Port 21 (FTP): Usually transmits passwords in plain text. Consider using SFTP (Port 22) instead.
• Port 23 (Telnet): Completely insecure. Replaced by SSH.
• Port 3306 (MySQL): Should NEVER be open to the public internet. Restrict access to localhost or specific IPs.
• Port 3389 (RDP): A common target for brute-force attacks on Windows servers.

Result Interpretation

Open: The service is listening and reachable.
Closed: The port is reachable but no service is listening.
Filtered: A firewall is blocking the scan (Best Security Practice).