Why enterprises need more than firewalls and intrusion detection systems

At the approach of the next millenium, enterprises are facing a lot of challenges and have to decide in which direction their communication networks will evolve. At the moment we see a large shift towards using global intranets and extranets. Most of the time it is also necessary to connect these networks to the Internet. During the consultancy work we provided in this area we concluded that although there are good tools available to protect these intranets from external attackers, perfect security could not be obtained. Therefore we started the TACK project to illustrate this by working out attacks that could be launched at any intranet. In these attacks we use the technology that is on the one hand rendering the Internet extremely successful but on the other hand facilitates the work for attackers. This paper summarizes the results of this project. We conclude that fundamentally no intranet can be made completely secure.