EDIT: My VPN has port forwarded a 5-digit tcp/udp port for me.
What kind of attacks am I opening the computer to with VPN port forwarding?
Any open port is susceptible to probes/attacks, it all depends on what service/application is running on it and how vulnerable is that service/application itself.
- If using application, you need to find out how vulnerable is your VPN application.
- What cipher suits are used.
- Implement strong authentication measures.
- Keep log of connections.