CVE-2025-20219

MEDIUM
Published Aug 14, 2025 Modified Apr 15, 2026 CWE-284

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.

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CVSS v3.1 Score

5.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Weakness Type (CWE)

CWE-284 CWE-284

References

Frequently Asked Questions

What is CVE-2025-20219? +
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. It has a CVSS v3.1 base score of 5.3 (MEDIUM).
How severe is CVE-2025-20219? +
CVE-2025-20219 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
How do I check if I'm vulnerable to CVE-2025-20219? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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