CVE-2021-1231 Cisco Nexus 9000 Series Fabric Switches ACI Mode Link Layer Discovery Protocol Port Denial of Service Vulnerability
An unauthenticated adjacent attacker can disable switching on an SFP interface by sending a crafted LLDP packet, disrupting network traffic on Cisco Nexus switches.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-1231?
CVE-2021-1231 is a medium-severity denial of service vulnerability in Cisco Nx-Os, published on 24 Feb 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A vulnerability in the Link Layer Discovery Protocol (LLDP) for Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an unauthenticated, adjacent attacker to disable switching on a small form-factor pluggable (SFP) interface. This vulnerability is due to incomplete validation of the source of a received LLDP packet. An attacker could exploit this vulnerability by sending a crafted LLDP packet on an SFP interface to an affected device. A successful exploit could allow the attacker to disable switching on the SFP interface, which could disrupt network traffic.
Which versions are affected by CVE-2021-1231?
It affects 1 product.
Products include Cisco Nx-Os.
How do I fix CVE-2021-1231?
No fix has been published for CVE-2021-1231 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-2021-1231 being exploited?
There is no known exploitation of CVE-2021-1231 in the wild and no public exploit code.
Other vulnerabilities in Cisco Nx-Os
Sources
Also known as GHSA-hpqm-fqwv-8ffg.