Remediation Verification: Open Ports

⇤ Remediation Verification

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.

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