Security hole please fix asap

I have had a bonuch of people saying that there is a security hole in the server softwere please can u fix asap please

update
Just when back on my server and tnt and the console commands were used

 

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"Security hole" is kind of a broad term. Care to be a bit more specific, perhaps?

Oh, an update, ignore the picture

What do the server logs say?

 

The server logs say Server shutting down by then it ends and do not say who it was but when i rejoin the server and take a look in the commands log witch is a plugin i have it just says Server stooped by and ends that is it

 

Are you sure it isn't a plugin or that you have configured the permissions incorrectly?

 

Nope there is no permissions plugin set yet

 

Did you give everyone op access? They may just be doing a /stop.

 

Not that no one trusts you; but you will get more help posting actual logs and not your interpretation of them. A list of plugins you use and perhaps some config files would help also.