Today Roger Grimes posted an article on InfoWorld about the overdue death of the firewall: Why you don’t need a firewall. His case rests on two primary arguments: 1. The firewall doesn’t protect against modern day threats, specifically client-side vulnerabilities and the fact that all apps run over port 80 and 443 that can never be blocked in the firewall and 2. The firewall is managed so poorly that it causes more problems than it solves.
Let’s separate these two points to more logically discuss each, starting with the value of a firewall in today’s threat environment. I take significant issue with his statement that, Today, 99 percent of all successful attacks are client-side attacks. This is not substantiated by any research for good reason; it isn’t true. The Verizon Data Breach Investigations Report actually discusses successful attacks in significant depth and completely invalidates this point. It reports that 81% of all attacks and 99% of lost data is a direct result of Hacking. It goes on to specify that access to remote services (e.g. VNC, RCP) combined with default, weak or stolen credentials account for 88% of all breaches. The assumption that 99% of attacks are client-side is dead wrong.
With remote access to services remaining the greatest attack vector today, firewalls still play a very significant role and are changing dramatically. It would also seem that Roger is ignoring new advancements in firewall technology. NextGen firewalls are specifically adept at helping prevent the client-side attack. No longer is port 80 and 443 an open highway of access through which everything can pass. User-based and application-based policies permit effective control of outbound access.
Roger’s second point, on ineffective management, is something which I agree is a problem, but don’t agree with his conclusion. His argument that ineffective management, where rules are created that permit nearly all access renders the firewall useless, is absolutely correct. Ineffective management that leads to poor configurations is a problem that can turn the best firewall technology into nothing more than a router passing all traffic. But his conclusion that this means the firewall should die is a really bad leap in logic. Poor management is not cause to kill the technology. Instead, I propose more effective management.
FireMon has been dedicated to this very idea of better firewall management for over a decade. Ineffective firewalls are not a caused by bad technology or incapable administrators. It is a problem with management. A stream of 1,000 logs per second won’t make any sense if a human tries to process their meaning while staring at a screen, but with some automation of log analysis, they can provide a wealth of information. 500 complex rules in a single firewall policy may be nearly impossible to evaluate to understand what access is truly being allowed, but with a powerful policy analysis tool, it is a trivial exercise. Even Roger’s example of a poorly defined rule with ANY ANY defined due to missing requirements is a solvable problem with the right tools. FireMon provides a powerful Traffic Flow Analysis tool that analyzes traffic flowing through overly-permissive rules permitting retroactive correction of these problematic rules.
The firewall is not dead and won’t be. With next gen capabilities and effective management – which is possible and available today – the firewall will remain a critical component of security solutions forever.