[Samba] Possible security issue with DHCP script.

[Zombie Ryushu]

I use a Strongswan VPN to connect via IPSec over VPN. Due to an error on 
my part, I set the user identity to olympia.pukey (192.168.0.4) - which 
is the hostname to one of my Domain Controllers. I use the script for 
Kerberized updates with Bind DLZ, and it accepted the zone update, 
changing the A Record to 192.168.0.234, the DHCP lease given by dhcpd. 
This broke domain Authentication. There is no check in the script to see 
if a DC occupied that hostname. I was able to manually fix it back. This 
could be used by a malicious actor to intercept domain logins.