CVE-2025-20219
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Access Control Bypass Vulnerability
Description
A vulnerability in the implementation of access control rules for loopback interfaces in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to send traffic that should have been blocked to a loopback interface. This vulnerability is due to improper enforcement of access control rules for loopback interfaces. An attacker could exploit this vulnerability by sending traffic to a loopback interface on an affected device. A successful exploit could allow the attacker to bypass configured access control rules and send traffic that should have been blocked to a loopback interface on the device.
Weakness: CWE-284
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
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Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Access Control Rules Bypass Vulnerability
Cisco’s rating: Medium (advisory CVSS 5.3) · Published Aug 14, 2025
Bug IDs: CSCwi57783 , CSCwn19639
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from