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CVE-2025-20219

MEDIUMCVSS 5.3/10EPSS 0.36%

Last modified

CVE-2025-20219 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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. EPSS estimates a 0.36% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
5.3/10

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

EPSS Probability
0.36%

27.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published
Last Modified
Status
Deferred

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.
How severe is CVE-2025-20219?
CVE-2025-20219 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.
How do I fix CVE-2025-20219?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-20219?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST