CPU load-based countermeasure technique for intelligent DoS attack targeting firewalls

Abstract

DoS attacks pose one of the most serious threats to firewalls which are considered as the first line of defence in any network. An attacker may use potential probing technique to discover last matching rules of a firewall rule set and hence trigger low-rate DoS attack that floods the firewall with traffic targeting rules at the bottom of policy. We propose a countermeasure technique in which DoS attack is detected by observing CPU load and ask all clients to solve a computational difficult problem and servicing the clients that provide the result. © 2014 Springer India.