Stored procedure body missing
Yes, this is possible, no body required. How it got this way? Your guess is as good as ours. It is easy to do but we can't possibly know whether this was human error or some kind of truncation from a script or tool.

CREATE PROCEDURE dbo.blat
AS
GO
EXEC dbo.blat;


Output:


  Command(s) completed successfully.


Good to have source control to sort this kind of thing out. 

If you're concerned, though, you should check your application and the rest of the procedures to see if anything calls this empty procedure and actually expects it to do anything. Error handling, unit tests, etc. may be passing simply because it isn't throwing an error.