Vulnerability Monitor

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CVE-2021-1389


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.


Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 5.8, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts limited integrity, for affected systems. Impacting 12 products from cisco, from cisco, from cisco and 9 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2021-02-04T17:15:18.937

Last Modified

2024-11-21T05:44:14.533

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 5.8 (MEDIUM)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:P/I:P/A:N

  • Access Vector: NETWORK
  • Access Complexity: LOW
  • Authentication: NONE
  • Confidentiality Impact: PARTIAL
  • Integrity Impact: PARTIAL
  • Availability Impact: NONE
Exploitability Score

10.0

Impact Score

4.9

Weaknesses
  • Type: Secondary
    CWE-284
  • Type: Primary
    NVD-CWE-Other

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Operating System cisco ios_xr < 6.6.3 Yes
Operating System cisco ios_xr 7.1.0 Yes
Operating System cisco ios_xr 7.2.0 Yes
Hardware cisco ncs_540 - No
Hardware cisco ncs_5501 - No
Hardware cisco ncs_5501-se - No
Hardware cisco ncs_5502 - No
Hardware cisco ncs_5502-se - No
Hardware cisco ncs_5508 - No
Hardware cisco ncs_5516 - No
Hardware cisco ncs_560 - No
Operating System cisco nx-os - Yes
Hardware cisco nexus_3600 - No
Hardware cisco nexus_9500_r - No

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For cisco's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.