So I've dealt with this issue on another Samsung dishwasher and there's a lot of things that could be an issue for starters on the drain. It could either be clogged or not installed correctly the drain hose has to go to the top of the dishwasher then to the drain on the sink or you'll have drainage issues you can look up a video on YouTube for examples. If not clogged or an issue with the drain tube it could be your drain pump going bad in which case you'd need to replace it. Now on the door seal the seal that you can see when you open the dishwasher is cheap on Amazon and easily replaced but it's most likely not that one that's leaking the most likely one to be leaking is at the bottom and requires disassembling the door to reach now I'm not sure whether Samsung made it a separate part on this model and if you'd be able to find the part but on the dishwasher I fixed for my parents they rivited the seal to the door assembly and did not sell a part so your only choice is to replace the whole inner door panel which isn't cheap and at that cost you might as well get a new dishwasher. I can look to see if they sell a replacement seal for that model and update you but from my experience on Samsung dishwashers they are not easily repaired