Remediation Verification: Open Ports

Open Ports grading is based on the status of the port. Use the Nmap and telnet commands to check IP addresses and ports and see:

• If a port is open. A “filtered” port implies that it’s closed.
• Services running on the port.
• Vulnerabilities.

We cannot confirm if UDP ports are truly closed since they do not require a handshake. Therefore, the finding cannot be updated and will have to go through its entire lifetime. However, if a UDP call returns “open|filtered,” then it is likely (but not always!) closed.

Commands requiring specific asset data from your finding to be inserted (variables) are indicated by the bold text.

Learn more about remediation verification.

Nmap

nmap -Pn -p port IP Address

The -u flag is required only when testing UDP ports.

Telnet

See available options for connecting over a specific IP or port.

telnet IP address port