CVE-2025-20243
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerability
Severity
High 8.6
CVSS 3.1
Exploited
Not listed
EPSS
0.006
44.6th percentile
Discovered by
Vendor
Published by the vendor
Published
Aug 14, 2025
Assigned by cisco
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.
Weakness: CWE-835
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Adaptive Security Appliance (ASA) | Firewall / NGFW | cna-assigner |
| Cisco | Cisco Firepower Threat Defense (FTD) | Firewall / NGFW | cna-assigner |
Vendor-reported affected versions (2)
- Cisco · Cisco Adaptive Security Appliance (ASA) Software
- Cisco · Cisco Firepower Threat Defense Software