CVE-2021-1389
5.8 · MEDIUMOverview
CVE-2021-1389 is a medium-severity vulnerability affecting cisco ios_xr. It was published on February 4, 2021 and has a CVSS 3.1 base score of 5.8 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.8, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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
Check the references section for vendor advisories and patches from cisco. Update ios_xr to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| cisco | ios_xr | >= 0, < 6.6.3 | Affected |
Frequently Asked Questions
What is CVE-2021-1389?
CVE-2021-1389 is a medium-severity vulnerability affecting cisco ios_xr. It was published on February 4, 2021 and has a CVSS 3.1 base score of 5.8 (MEDIUM).
How severe is CVE-2021-1389?
This vulnerability has a CVSS 3.1 base score of 5.8, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-1389?
Check the references section for vendor advisories and patches from cisco. Update ios_xr to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-1389?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-1389 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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