There was an occasion about 20 years ago when my boss and I needed to make some urgent changes to a paper that was going to the board the next day. His secretary had just gone off on a walking holiday, and the document was secure in her section of the company system.
It took the two of us about five minutes to "hack" the security system, change her password, and do the necessary to access the document.
Like all security, it's only as good as the people thinking about it. They will armour plate and treble-secure the front door, windows etc. But they'll leave the back door open for the staff to come and go. Anyone with a bit of nous can get in that way.
Not much has changed in those 20 years.