CVE-2021-1590 Cisco NX-OS Software system login block-for Denial of Service Vulnerability
An unauthenticated remote attacker can cause a login process restart via brute-force attacks, resulting in a denial of service on Cisco NX-OS devices.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-1590?
CVE-2021-1590 is a medium-severity denial of service vulnerability in Cisco Nx-Os, published on 25 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-787
Which versions are affected by CVE-2021-1590?
It affects 2 products.
Products include Cisco Nx-Os, Cisco Unified Computing System.
How do I fix CVE-2021-1590?
No fix has been published for CVE-2021-1590 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-1590 being exploited?
There is no known exploitation of CVE-2021-1590 in the wild and no public exploit code.
Other vulnerabilities in Cisco Nx-Os
Sources
Also known as GHSA-g2wr-78c7-xc4v.