David B. wrote:

my BT Home Hub routers have come with a factory preset Wireless Network
Name, a 12 digit Wireless Password/key and also an Admin Password for
the Hub Manager.

Why is there a need to change these if no one else has physical access
to the router?

DNS Rebinding plus tempting someone to visit an attack website, in this
case Hyperoptic/ZTE routers, rather than BT

https://contextis.com/en/resources/advisories/hyperoptic-zte-home-routers