CVE-2024-20293: A vulnerability in the activation of an access control list (ACL) on Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defen...

Description

A vulnerability in the activation of an access control list (ACL) on Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass the protection that is offered by a configured ACL on an affected device. This vulnerability is due to a logic error that occurs when an ACL changes from inactive to active in the running configuration of an affected device. An attacker could exploit this vulnerability by sending traffic through the affected device that should be denied by the configured ACL. The reverse condition is also true—traffic that should be permitted could be denied by the configured ACL. A successful exploit could allow the attacker to bypass configured ACL protections on the affected device, allowing the attacker to access trusted networks that the device might be protecting. Note: This vulnerability applies to both IPv4 and IPv6 traffic as well as dual-stack ACL configurations in which both IPv4 and IPv6 ACLs are configured on an interface.

Metrics

CVSS 3.1

5.8/10

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

EPSS Probability

0.40%

31.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-436

Affected Software

Vendor	Product	Versions
Cisco	Adaptive Security Appliance Software	>= 9.19.1, <= 9.19.1.24
Cisco	Adaptive Security Appliance Software	9.20.1
Cisco	Adaptive Security Appliance Software	9.20.1.5
Cisco	Firepower Threat Defense	>= 7.3.0, <= 7.4.0

References

Timeline

Published: May 22, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2024-20293?

A vulnerability in the activation of an access control list (ACL) on Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass the protection that is offered by a configured ACL on an affected device. This vulnerability is due to a logic error that occurs when an ACL changes from inactive to active in the running configuration of an affected device. An attacker could exploit this vulnerability by sending traffic through the affected device that should be denied by the configured ACL. The reverse condition is also true—traffic that should be permitted could be denied by the configured ACL. A successful exploit could allow the attacker to bypass configured ACL protections on the affected device, allowing the attacker to access trusted networks that the device might be protecting. Note: This vulnerability applies to both IPv4 and IPv6 traffic as well as dual-stack ACL configurations in which both IPv4 and IPv6 ACLs are configured on an interface.

How severe is CVE-2024-20293?

CVE-2024-20293 has a CVSS score of 5.8/10 (MEDIUM severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.

How do I fix CVE-2024-20293?

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.