For one, the processing power needed to run the firewall software detracts from the resources available to run Web applications, thus slowing down those applications. More importantly, the applications can become security holes. A hacker could send out a network probe to identify the Web server and then use the server to bypass the firewall and access the corporate network. Yet even installing a firewall on a stand-alone system does not eliminate all security concerns. Overall protection is only as good as a company's weakest link.
Many corporate networks harbor other holes for hackers.
Minn. Companies can take steps to hinder hackers from doing much damage. At Eastern Kentucky University, for instance, users cannot change or update files accessed from the Web server. If such update capability were allowed, a hacker could use it to slip onto the server programs that give him or her control of the university's computer and network resources. The downside to this policy is that the university cannot install on the Web server any application that employees would want or need to update, such as human resources applications. While vendors such as Secure Computing have begun developing systems that can, for example, distinguish an intruder's call from that of a supplier, administering such a system can quickly become cumbersome.