Description

A vulnerability in the access control list (ACL) processing in the egress direction of Cisco IOS XR Software could allow an unauthenticated, remote attacker to bypass a configured ACL.

This vulnerability exists because certain packets are handled incorrectly when they are received on an ingress interface on one line card and destined out of an egress interface on another line card where the egress ACL is configured. 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 egress ACL on the affected device.
For more information about this vulnerability, see the section of this advisory.
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Classification

CVE ID: CVE-2025-20145

CVSS Base Severity: MEDIUM

CVSS Base Score: 5.8

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

Affected Products

Vendor: Cisco

Product: Cisco IOS XR Software

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 4.63% (scored less or equal to compared to others)

EPSS Date: 2025-04-10 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-20145
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-modular-ACL-u5MEPXMm
https://blog.apnic.net/2024/09/02/crafting-endless-as-paths-in-bgp/

Timeline