Conclusion

The IT world is far from secure. There are plenty of people eager to gain illegal access to critical information. What's more, sensation-seeking young people discover computers (and hacking) every day, and imagine they can hack with impunity, being physically far from their victim. At the same time, they discover the existence of a host of ready-made attack tools, sparing them the tedious task of learning how to carry out their crimes. As a result, every day hundreds of attacks are launched against the same (ordinary) server, and the trend is not getting any better.

To limit the risk of a system being hacked, it is therefore necessary to reduce the services it offers as much as possible, to confine servers accessible from untrustworthy networks to specialized networks (such as a DMZ: Demilitarized Zone), and to reduce to the strict minimum the system's interactions...