Cisco Firepower Threat Defense (FTD) and Cisco Adaptive Security Appliances Software (ASA Software) are both products of Cisco U.S.A. Cisco Firepower Threat Defense is a set of unified software that provides next-generation firewall services.Cisco Adaptive Security Appliances Software is a firewall and network security platform. Cisco Firepower Threat Defense and Cisco Adaptive Security Appliances Software have a denial of service vulnerability that can be exploited by attackers to cause high CPU utilization, resulting in a denial of service.