CVE-2025-20137

Description

A vulnerability in the access control list (ACL) programming of Cisco IOS Software that is running on Cisco Catalyst 1000 Switches and Cisco Catalyst 2960L Switches could allow an unauthenticated, remote attacker to bypass a configured ACL. This vulnerability is due to the use of both an IPv4 ACL and a dynamic ACL of IP Source Guard on the same interface, which is an unsupported configuration. An attacker could exploit this vulnerability by attempting to send traffic through an affected device. A successful exploit could allow the attacker to bypass an ACL on the affected device. Note: Cisco documentation has been updated to reflect that this is an unsupported configuration. However, Cisco is publishing this advisory because the device will not prevent an administrator from configuring both features on the same interface. There are no plans to implement the ability to configure both features on the same interface on Cisco Catalyst 1000 or Catalyst 2960L Switches.

Category

4.7
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.03%
Affected: Cisco IOS
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2025-20137?
CVE-2025-20137 has been scored as a medium severity vulnerability.
How to fix CVE-2025-20137?
To fix CVE-2025-20137, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2025-20137 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2025-20137 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-20137?
CVE-2025-20137 affects Cisco IOS.
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