RV340 Ports Stay Open Despite Port Forwarding Disabled For These Ports

[hfredrics]

We have a Cisco RV340 Router.  I've set up port forwarding and triggering rules with no problem for all of the ports we want to have open.  However, there are two incoming ports, RDP 3389 and VNC 5900 which appear to be open to the internet despite being 100% certain that port forwarding is NOT enabled for these ports.  I have searched far and wide in the router's configuration panel to no avail, and can't find these ports as having been enabled.  

Is there a known bug with this router that leaves certain ports open without any indication within the software that these ports have been opened?

Thanks in advance!

[pieterh]

you provide little facts about the current configuration.
my suggestion is to check if you have UPnP enabled ?
Configuration of Universal Plug and Play (UPnP) on RV320 and RV325 Routers - Cisco
with this option a router can respond to a client request to open port-forwarding "automagically"

[Rich R]

Yes exactly what I was going to say too.

You say "open" but depends what you mean by that.  Open usually means the device is listening itself on those ports but it wouldn't make any sense for the router itself to be receiving those ports unless it has malware installed that's doing that.  The other possible meaning is forwarding - in which case where is it forwarding that traffic to?  The device it's forwarding to will be the one which has requested the UPnP "pinhole" to be punched through.