Multiple vulnerabilities (CVE-2021-1573, CVE-2021-34704, CVE-2021-40118) in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition.

These vulnerabilities are due to improper input validation when parsing HTTPS requests. An attacker could exploit these vulnerabilities by sending a malicious HTTPS request to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Source: cisco.com