CVE detail

CVE-2021-1389 — CVE-2021-1389

Published 2021-02-04 · Modified 2026-06-17 · Vendor cisco · Product ios_xr · Source nvd

MEDIUM

severity

CVSS-derived band

5.8

CVSS v3

0–10 scale

0.0122

EPSS probability

exploitation probability, 30d

66.0%

EPSS percentile

percentile vs all CVEs

NOT LISTED

CISA KEV

known exploited catalog

Description

A vulnerability in the IPv6 traffic processing of Cisco IOS XR Software and Cisco NX-OS Software for certain Cisco devices could allow an unauthenticated, remote attacker to bypass an IPv6 access control list (ACL) that is configured for an interface of an affected device. The vulnerability is due to improper processing of IPv6 traffic that is sent through an affected device. An attacker could exploit this vulnerability by sending crafted IPv6 packets that traverse the affected device. A successful exploit could allow the attacker to access resources that would typically be protected by the interface ACL.

Remediation

Product	Vulnerable range	Fixed version	Advisory
Cisco Cisco IOS XR Software	—	not specified	advisory ↗

References

cvedb.io · NVD · CISA KEV · FIRST EPSS · vendor advisories (CVE Program List v5). Informational only, no warranty — verify every remediation against the vendor advisory before acting on it. This product uses data from the NVD API but is not endorsed or certified by the NVD, CISA, FIRST.org or any vendor named. CVE® is a registered trademark of The MITRE Corporation.