CVE-2021-1590

Cisco NX-OS Software system login block-for Denial of Service Vulnerability

Description

A vulnerability in the implementation of the system login block-for command for Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a login process to unexpectedly restart, causing a denial of service (DoS) condition. This vulnerability is due to a logic error in the implementation of the system login block-for command when an attack is detected and acted upon. An attacker could exploit this vulnerability by performing a brute-force login attack on an affected device. A successful exploit could allow the attacker to cause a login process to reload, which could result in a delay during authentication to the affected device.

Category

5.3
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.82% Top 30%
Vendor Advisory cisco.com
Affected: Cisco Cisco NX-OS Software
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2021-1590?
CVE-2021-1590 has been scored as a medium severity vulnerability.
How to fix CVE-2021-1590?
To fix CVE-2021-1590, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-1590 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-1590 is being actively exploited. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-1590?
CVE-2021-1590 affects Cisco Cisco NX-OS Software.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.