This chapter has given you some exposure to the kinds of security issues that can affect firewall systems. You've seen how attacks against firewalls typically involve tricking the firewall into violating its rule-base or facilitating an attacker in impersonating another system. These types of attacks are particularly significant when you consider that firewalls are devices charged with protecting the borders of almost every network. From an auditing perspective, firewalls provide a unique and very worthwhile project. Reviewing firewall software can be particularly interesting, as it requires a creative use of networking protocols, and there's a heavy focus on design and logic review. It's also an area that's currently lacking in extensive investigation, so it's a good place for a vulnerability researcher to cover new ground. |