[Oracle’s system is as secured as one would expect a hacker, vigilante, and generally suspicious individual’s systems should be. The problem is that it's not how a regular citizen's should be. The security befits something incredibly sophisticated, more like military or governmental agencies, not a tiny little apartment nearby.
Layer atop layer atop layer is how her security goes, each wall set up more strong than the last, the inner firewalls extremely harder to get through than the subsequent outer ones. Knocks on her computer doors are easily brushed aside, and more sophisticated poundings and pressure won’t normally make it fall. It can withstand someone poking at it’s weaknesses but not with the speed and accuracy that Finn is. It doesn’t anticipate someone with the ease his ability grants him.
The first layer of security crumbles, letting him take a peek at the second, stronger door in place.]