Serious issue with CraftBukkit

This appears to be an exploit of some kind.



Basically, when a certain player tries to log on. Only that player. The server crashes.

EDIT: Deleted the player.dat of the person and it fixed the problem, but am still curious to what this is.

player.dat File of the person who was causing this: https://github.com/downloads/wjcrouse913/Sunscreen/NBTT.dat

 

Well if you moved the player.dat instead of deleting it there would be a chance for someone to take it and test it for exploits, but you destroyed that, so There's nothing to do now.

 

Oh, well, it actually did happen again with the same player a few hours later so I will attach the player.dat if it happens again.

EDIT: It was in my trash so here...

 

Does he have Java Runtime 6 Update 25?

 

From the error, and taking a quick look at the source, it looks like there's a problem with a furnace in the vicinity of the player, most likely it contains an invalid item (Maybe due to the player running a client mod and the server not checking item number validity, I'm not positive, didn't spend that much time looking at it). The error should pop up if any player goes near that same location though.