A vulnerability in the access control list (ACL) processing on MPLS interfaces in the ingress direction of Cisco IOS XR Software could allo…

published 2023-09-13 3y ago modified 2026-06-17 4mo ago also EUVD-2023-24370

cvss: 5.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits: 0; none known

A vulnerability in the access control list (ACL) processing on MPLS interfaces in the ingress direction of Cisco IOS XR Software could allow an unauthenticated, remote attacker to bypass a configured ACL. This vulnerability is due to incomplete support for this feature. 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. There are workarounds that address this vulnerability.

This advisory is part of the September 2023 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2023 Semiannual Cisco IOS XR Software Security Advisory Bundled Publication .

Patch / fix

fixed in 1

cisco ios_xr 7.7.21, 7.9.2

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Exploit prediction

0.60% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-14).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

Cisco Cisco IOS XR Software

Classification

Weakness

CWE-284 Improper Access Control
CWE-863 Incorrect Authorization

Technology feeds

Cisco IOS rss critical rss

References

sec.cloudapps.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-dnx-acl-PyzDkeYF
vendor-advisory

Sources

CVE List CVE-2023-20191
NVD CVE-2023-20191

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