A flaw in Cisco Secure Firewall’s Remote Access SSL VPN service trusts user input without validation, allowing an attacker to send crafted packets that exhaust device memory. The result is a denial of service that affects new VPN connections and may cause the device web interface to become temporarily unresponsive, while the management interface itself is not directly impacted.

Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software are the impacted products. No specific affected firmware versions are listed in the vendor advisory; administrators should verify the version of the deployed device against the advisory.

The CVSS score of 8.6 classifies the vulnerability as high severity. The EPSS score is below 1%, indicating a low to moderate likelihood of public exploitation, though the device remains exposed to remote attackers that can reach the VPN service. The attack is inferred to be remote, unauthenticated, and leveraging the exposed SSL VPN port. Successful exploitation leads to memory exhaustion, DoS of the VPN service, and potential degradation of the web interface, hindering administrative access.