When I turned on my garden hose bib today it caused a huge leak at the connection of the hose bib copper pipe and the indoor plumbing plastic pipes, resulting in lots of water in my basement. The leak stopped once I turned off the outside hose bib. What do I need to replace/fix so I can use the bib safely? Does the hose bib, copper pipe through the masonry and the connection to the plastic pipes all need to be replaced?

Was the hose bib slanted to the outside for drainage? Too often that is forgotten and then it doesn't fully drain and freezes and splits past the shutoff area. Then when its turned on it leaks everywhere and into the house.

I would pull that to inspect the copper to see if it split and go from there.