How do routers prevent automatic port forwarding from being abused

Question

I have a Verizon FIOS router and when I install most applications that need a port forwarded, magically the entry is automatically set up in the router. I searched on google and found out this is because of something called uPnP.

What keeps rogue applications from automatically adding entries to the port forwarding list? I never even see a popup or dialog that asks for permission when it comes to these automatic entries.

Answer 1

Nothing. It is potentially a large security hole. However, because of the variety of routers and firewalls out there, most malware will just rely on a connection from the infected system to a controller.

Answer 2

Nothing prevents applications from adding entries. That's why it's highly recommended that you disable uPnP. Any port forwards you need can be easily set up manually.