CVE-2025-20251
Cisco Secure Firewall Adaptive Security Appliance and Cisco Secure Firewall Threat Defense Software Authenticated Arbitrary File Deletion
Description
A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker to create or delete arbitrary files on the underlying operating system. If critical system files are manipulated, new Remote Access SSL VPN sessions could be denied and existing sessions could be dropped, causing a denial of service (DoS) condition. An exploited device requires a manual reboot to recover. This vulnerability is due to insufficient input validation when processing HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to create or delete files on the underlying operating system, which could cause the Remote Access SSL VPN service to become unresponsive. To exploit this vulnerability, the attacker must be authenticated as a VPN user of the affected device.
Weakness: CWE-1287
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Adaptive Security Appliance (ASA) Check your version | Firewall / NGFW | cna-assigner |
| Cisco | Cisco Firepower Threat Defense (FTD) Check your version | Firewall / NGFW | cna-assigner |
Vendor-reported products (2)
- Cisco · Cisco Adaptive Security Appliance (ASA) Software
- Cisco · Cisco Firepower Threat Defense Software
Vendor advisory
cisco-sa-asaftd-http-file-hUyX2jL4
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software VPN Web Server Denial of Service Vulnerability
Cisco’s rating: High (advisory CVSS 8.5) · Published Aug 14, 2025
Bug IDs: CSCwo00141 , CSCwo00880
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from