I see in FW config (cgi-bin/iptables.cgi) that INPUTFW are REDINPUT are after OVPNINPUT: therefore any block rule created for RED or Firewall input (using cgi-bin/firewall.cgi) does not apply to OpenVPN service.
How do you block through WebUI (cgi-bin/firewall.cgi) IP addresses to connect to your OpenVPN?
For the record, I have a FW Group called Bad Guys that is blocked in all chains: “Firewall Rules” - both in and out, " Incoming Firewall Access" - incoming, " Outgoing Firewall Access" - outgoing.
Basically I used all options cgi-bin/firewall.cgi offers, but that does not protect OpenVPN.
I am aware that I can use firewall.local, but this is burden - anything I put in cgi-bin/firewall.cgi, I also have to copy in firewall.local.
In my oppinion, OVPNINPUT should be protected by REDINPUT or INPUTFW…
I did a test: I added a rule as you suggested: I do not see it landing in OVPNBLOCK (this chain is in front of OVPNINPUT, OVPNINPUT contains the rules for allowing OPenVPN traffic). The rules land in chains that are after OVPNINPUT - so using GUI I can’t block any access to OpenVPN. (apart from location block and HOSTILE that are in front of OVPNINPUT)
And, for clarity, the existing rules are constructed using “any” in each of the FW entry, therefore my expectation was that “any” also protects OpenVPN service. My surprise when I found it did not protected OpenVPN was big.
I believe that the OVPINPUT chain is dealt with earlier to make sure that any rules put into the FW WUI will not accidentally block the OpenVPN Operation. If OVPINPUT came before the Firewall WUI then any rule added there could block or interfere with the OpenVPN traffic.
The OpenVPN access is well protected with the choice of encryption protocol and the addition of TLS Channel protection. If additional rules are wanted/required for the OpenVPN interface then that is what firewall.local is intended for.