A vulnerability in the web UI of Cisco FXOS and Cisco UCS Fabric Interconnect Software could allow an unauthenticated, remote attacker to cause a buffer overflow on an affected system. The vulnerability is due to incorrect input validation in the web UI. An attacker could exploit this vulnerability by sending a malicious HTTP or HTTPS packet directed to the physical management interface of an affected system. A successful exploit could allow the attacker to cause the process to crash and possibly reload the device, resulting in a denial of service (DoS) condition on the affected system. This vulnerability affects Firepower 4100 Series Next-Generation Firewall, Firepower 9300 Security Appliance, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvb61398, CSCvb86799.