Michigan State University
Firewalls are critical security devices handling all traffic in and out of a network. When under heavy load of both malicious and legitimate traffic, firewalls may be overloaded and start discarding or permitting packets without checking firewall rules, which can cause huge revenue losses or security breaches. In this paper, the authors study Denial of Firewalling attacks, where attackers use well-crafted traffic to effectively overwhelm a firewall. They first investigate firewall implementation characteristics that can be exploited for such attacks while treating the firewall as a black box.