Yes. When the attacker can interpose their own server on the network, seen by valid clients, then the attacker can redirect the DNS of those clients to the fak

Yes. When the attacker can interpose their own server on the network, seen by valid clients, then the attacker can redirect the DNS of those clients to the fake server. This is a MiTM attack that allows the fake server to be accepted by valid clients (on that network), stealing their credentials and then potentially their information from the server. There are actually many attacks that can happen here, one of which is simply to record the credentials, while passing the traffic through to the server and back from the server to the clients. Even though the true DNS server has had its DNS record's IP address changed to point towards the correct and true server, the clients are unaware of this change, as their DNS caches have been poisoned to point towards the malicious server. PS There is a defense against this, certificate pinning, but that is not used much in practice.