Vulnerability · Published Aug 14, 2025 · Assigned by cisco
CVE-2025-20243Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerability
High 8.6
In plain English
A high-severity infinite loop in Cisco Adaptive Security Appliance (ASA) Software from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities).
Official description
A vulnerability in the management and VPN web servers of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a DoS condition. This vulnerability is due to improper validation of user-supplied input on an interface with VPN web services. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web server on an affected device. A successful exploit could allow the attacker to cause a DoS condition when the device reloads.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Adaptive Security Appliance (ASA) Software | 9.12.39.8.39.12.19.8.19.12.29.8.2.459.8.29.8.4 |
| Cisco | Cisco Firepower Threat Defense Software | 6.2.3.146.4.0.16.2.3.76.2.36.4.0.26.2.3.96.2.3.16.2.3.2 |
Weakness: CWE-835 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H