CVE-2021-1361: A vulnerability in the implementation of an internal file management service for Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches...

Description

A vulnerability in the implementation of an internal file management service for Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode that are running Cisco NX-OS Software could allow an unauthenticated, remote attacker to create, delete, or overwrite arbitrary files with root privileges on the device. This vulnerability exists because TCP port 9075 is incorrectly configured to listen and respond to external connection requests. An attacker could exploit this vulnerability by sending crafted TCP packets to an IP address that is configured on a local interface on TCP port 9075. A successful exploit could allow the attacker to create, delete, or overwrite arbitrary files, including sensitive files that are related to the device configuration. For example, the attacker could add a user account without the device administrator knowing.

Metrics

CVSS 3.1

9.1/10

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

EPSS Probability

1.57%

72.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-552

Affected Software

Vendor	Product	Versions
Cisco	Nx-Os	9.3\(5\)
Cisco	Nx-Os	9.3\(6\)

References

Timeline

Published: Feb 24, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-1361?

A vulnerability in the implementation of an internal file management service for Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode that are running Cisco NX-OS Software could allow an unauthenticated, remote attacker to create, delete, or overwrite arbitrary files with root privileges on the device. This vulnerability exists because TCP port 9075 is incorrectly configured to listen and respond to external connection requests. An attacker could exploit this vulnerability by sending crafted TCP packets to an IP address that is configured on a local interface on TCP port 9075. A successful exploit could allow the attacker to create, delete, or overwrite arbitrary files, including sensitive files that are related to the device configuration. For example, the attacker could add a user account without the device administrator knowing.

How severe is CVE-2021-1361?

CVE-2021-1361 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 1.57% probability of exploitation in the next 30 days.

How do I fix CVE-2021-1361?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.