CVE-2021-1389 - CVE House
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Status published Medium CVE-2021-1389

Cisco IOS XR and Cisco NX-OS Software IPv6 Access Control List Bypass Vulnerability

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

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Affected Vendor

Affected Software

Cisco IOS XR Software
Vulnerable Versions:
Unknown

Timeline

Official Publish: February 4th, 2021
Last Modified: November 8th, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Weaknesses (CWE)

CWE-284

MITRE ATT&CK TTPs

T1190 Exploit Public-Facing Application
Initial Access
T1068 Exploitation for Privilege Escalation
Privilege Escalation
T1078 Valid Accounts
Persistence
T1213 Data from Information Repositories
Collection
T1565.002 Stored Data Manipulation
Impact