CVE-2025-20219

Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Access Control Bypass Vulnerability

View on CVE.org

Published Aug 14, 2025 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed

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.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Cisco

Cisco Adaptive Security Appliance (ASA) Software

unknown

Version	Status	Constraints
`9.18.2`	affected	—
`9.18.2.5`	affected	—
`9.18.2.7`	affected	—
`9.19.1`	affected	—
`9.18.2.8`	affected	—
`9.18.3`	affected	—
`9.19.1.5`	affected	—
`9.19.1.9`	affected	—
`9.18.3.39`	affected	—
`9.19.1.12`	affected	—
`9.18.3.46`	affected	—
`9.19.1.18`	affected	—
`9.18.3.53`	affected	—
`9.18.3.55`	affected	—
`9.18.3.56`	affected	—
`9.20.1`	affected	—
`9.19.1.22`	affected	—
`9.18.4`	affected	—
`9.20.1.5`	affected	—
`9.18.4.5`	affected	—
`9.19.1.24`	affected	—
`9.18.4.8`	affected	—
`9.20.2`	affected	—
`9.19.1.27`	affected	—
`9.18.4.22`	affected	—
`9.20.2.10`	affected	—
`9.19.1.28`	affected	—
`9.18.4.24`	affected	—
`9.20.2.21`	affected	—
`9.19.1.31`	affected	—
`9.18.4.29`	affected	—
`9.20.2.22`	affected	—
`9.18.4.34`	affected	—
`9.20.3`	affected	—
`9.18.4.40`	affected	—
`9.22.1.1`	affected	—
`9.20.3.4`	affected	—
`9.18.4.47`	affected	—
`9.20.3.7`	affected	—
`9.19.1.37`	affected	—
`9.20.3.9`	affected	—
`9.19.1.38`	affected	—
`9.18.4.50`	affected	—
`9.22.1.2`	affected	—

Cisco

Cisco Firepower Threat Defense Software

unknown

Version	Status	Constraints
`7.3.0`	affected	—
`7.3.1`	affected	—
`7.3.1.1`	affected	—
`7.4.0`	affected	—
`7.4.1`	affected	—
`7.4.1.1`	affected	—
`7.3.1.2`	affected	—
`7.6.0`	affected	—
`7.4.2`	affected	—
`7.4.2.1`	affected	—

No data.

Vendor	Product	Versions
Cisco	Adaptive Security Appliance Software	—
Cisco	Firepower Threat Defense Software	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

Source	ID	Title
EUVD	EUVD-2025-24848	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

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.426% probability within 30 days)

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-acl-bypass-mtPze9Yh

History

Aug 15, 2025 8:15 AM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Cisco Cisco adaptive Security Appliance Software Cisco firepower Threat Defense Software
Vendors & Products		Cisco Cisco adaptive Security Appliance Software Cisco firepower Threat Defense Software

Aug 14, 2025 6:15 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Aug 14, 2025 4:45 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
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.
Title		Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Access Control Bypass Vulnerability
Weaknesses		CWE-284
References		https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-acl-bypass-mtPze9Yh
Metrics		cvssV3_1 `{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}`