[chef] security of chef

[William Herry < >]

Hi

I've test chef for a while and I really like it, now we want integrate it with openstack for help configure instances, 

my boss want me to finger it out is it is safe to use chef like this, 
which I don't think it is, but always think about security is not much bad

here are the question he want to know

1. what info about chef server can client(instance) get?
2. is it easy to hack the chef server from client(if client already been cracked)?
3. if my chef server have been cracked, how do I know that?

I know chef have no such issue, I know it separated Authentication and Authorization
but I have to make sure and explain to my boss

thanks in advs