A big note to add: if you want a secure system, forget Ubuntu entirely and go with CentOS or RHEL with SELinux enabled and locked down correctly.
It's as damn near bullet proof as you can get.
It's as damn near bullet proof as you can get.
With SELinux root can build systems which are so secure that root himself cannot hack them.
Sounds like your administrator would be well served to spend more time studying real-world vulnerabilities and less time focusing on SELinux :)
See eg. http://grsecurity.net/~spender/exploits/exploit2.txt
So it technically would extinguish itself there and then.
It works on the principle of least privilege so you start with nothing and add what the process needs.