Cisco MDS 9000 NX-OS Software Denial of Service Vulnerability

A vulnerability in the supervisor of the Cisco MDS Family could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.

The vulnerability is due to improper handling of Virtual Router Redundancy Protocol (VRRP) frames. An attacker could exploit this vulnerability by sending a VRRP frame with Authentication Header (AH) authentication. An exploit could allow an attacker to drive CPU utilization over 90 percent, causing the supervisor to be slow to respond. The CPU does not recover until the VRRP service is restarted via a system switchover or restart.

Cisco has confirmed the vulnerability in a security notice and released software updates.

Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.