I have tried our configuration of UFW on a fresh Ubuntu 18.04.3 x86_64 and after that, I've made a NMAP test to see what port could be visible from the outside.
Guess what, you shouldn't use this configuration anymore...
Many ports are open, so I've tried a new firewall with many feature instead of UFW:
First download the csf.tgz package
wget https://download.configserver.com/csf.tgz
Then:
tar -xpvf csf.tgz
cd csf
Then run in the terminal:
./install.sh
./install.cpanel.sh
./install.cwp.sh
./install.cyberpanel.sh
./install.directadmin.sh
./install.generic.sh
./install.interworx.sh
./install.vesta.sh
To test the module paste this:
perl /etc/csf/csftest.pl
service csf start
Edit the /etc/csf/csf.conf
Use the readme file in the CSF folder
Add or suppress ports
service csf restart
You should try it, it works quite fine out of the box just edit one file /etc/csf/csf.conf
and you're good to go.
Cordially