Virtual private networking (VPN) companies market their services as a way to prevent anyone from snooping on your Internet usage. But new research suggests this is a dangerous assumption when connecting to a VPN via an untrusted network, because attackers on the same network could force a target’s traffic off of the protection provided by their VPN without triggering any alerts to the user.
Thanks for the detailed explanation. I think I get it now!
I did look into it with
ip route show
when using nothing vs portmaster vs openvpn and it is just like you said, when using openVPN it just creates additional routes with a higher priority, but the normal route is still open.