What Do Firewalls Protect?An Empirical Study of Firewalls, Vulnerabilities, and Attacks
- Author(s): Peisert, Sean
- Bishop, Matt
- Marzullo, Keith
- et al.
Firewalls are a cornerstone of how sites implement "defense in depth." Many security policies assume that outside attackers must first penetrate a firewall configured to block their access. This paper examines what firewalls protect against, and whether those protections are sufficient to warrant placing the current level of trust in firewalls.