I have used a long screw for fixing this exact issue. Timberlock or similar lag type. But you need to know what it is already attached to and how. Also be careful of wiring. Usually there is a joist or box beam to catch, but sometimes folks just use a 2x4 block.
I use the longest I think I need, and putty the new hole from the screw.
I try to put it as close to the bottom where it meets the floor.