A high-severity vulnerability in the Datagram TLS (DTLS) message handling of Cisco Secure Firewall ASA and FTD Software for 3100 and 4200 Series devices allows an unauthenticated remote attacker to cause a denial of service (DoS) by sending crafted DTLS traffic. The flaw arises from improper resource management during DTLS message processing, potentially causing the device to reload and disrupt service.