[devicenull]

Amusingly, there's a sticky about this exact topic.. https://forums.alliedmods.net/showthread.php?t=119214

[Visual77]

There is a few commands out there that does all that and has been working since the game was released (makes the server go to 100 % cpu so everyone loses connection to it)
KAC blocks it, but rcon_lock does not, so either install KAC or PM me for a .smx file.

A friend reported it to valve a few days ago and they are going to fix it in then next patch.
But that will probably be with the upcoming dlc they promised in may, which probably will be released in december