Port 22 is SSH, TCP.
TCP
medium risk
App-IDssh
Secure Shell — encrypted terminal access, file transfer (SFTP/SCP), and tunnelling.
Palo Alto
Create the service object for this port, then allow the App-ID on it. Restricting the rule to the port's service object keeps the rule working on a non-default port and stops the App-ID matching on other ports. Replace the placeholders with your own rule name and zones.
set service tcp-22 protocol tcp port 22
set rulebase security rules <rule-name> from <from-zone> to <to-zone> source any destination any application ssh service tcp-22 action allow
Risk and exposure
Rated medium risk. Restrict this port to the sources that need it and keep the service patched; avoid exposing it to the whole internet unless the service is meant to be public.
Check it
- Linux
ss -tlnp | grep :22 - PowerShell
Test-NetConnection <host> -Port 22 - nmap
nmap -p 22 <host>