Cisco has called on the users of its Email Security Appliance and Secure Email and Web Manager appliances with non-default configurations to immediately patch a critical security flaw, tracked as CVE-2022-20798, which could be abused to evade authentication and access the appliances' web management interface, according to BleepingComputer. "An attacker could exploit this vulnerability by entering a specific input on the login page of the affected device. A successful exploit could allow the attacker to gain unauthorized access to the web-based management interface of the affected device," said Cisco, which noted the flaw's discovery while addressing a Cisco Technical Assistance Center case. Only appliances leveraging external authentication with LDAP are impacted by the security bug, which has not yet been exploited by any threat actor, said Cisco's Product Security Incident Response Team. Impacted appliances could be verified by logging into the web-based management interface and checking whether the "Enable External Authentication" option has a green check box.