Looks like you have leaks and it also looks like you don’t drive too far cause the water vapour just sits on the pipes and rusts and doesn’t get a chance to burn off. Try and tighten the clamps. If that doesn’t work then have someone mig all the connections closed like the factory did.
If the clamps aren't crimping the pipe too much, you might be able to separate and use exhaust sealant...and retighten...however I bet this will be difficult even if pipes come apart. Probably a nice weld would be in order and easier here.
https://www.autozone.com/emission-c...p/walker-exhaust-exhaust-clamp-35723/276961_0 Walker makes them You can order them online or anywhere.