Because they are either using 0.1 or 0.2 to glitch through walls.
Amazing, never heard of this.
Sure you can make a mod to prevent, and force the clients to download it using a clientCmd/serverCmd check, but then the clients can modify it so they can still use it.
So in short, no, you can't make it Admin only.
Just warn / ban the users abusing the glitch. It's really the only option.