Cisco NX-OS Malformed ARP Header Denial of Service Vulnerability

A vulnerability in Address Resolution Protocol (ARP) feature of the Cisco Nexus Operating System (NX-OS) could allow an unauthenticated, adjacent attacker to cause a partial denial of service (DoS) condition because the ARP process unexpectedly restarts.

The vulnerability is due to improper input validation of the fields in the ARP packet header. An attacker could exploit this vulnerability by sending a crafted ARP packet from an adjacent network to the affected device. An exploit could allow the attacker to cause a partial DoS condition because the ARP process could unexpectedly restart when processing the crafted ARP packet.

Cisco has confirmed the vulnerability and software updates are available.

To exploit this vulnerability, an attacker must have access to the same broadcast or collision domain as the targeted device. This access requirement may reduce the likelihood of a successful exploit.

Although the CVSS indicates that software updates are not available to fix this vulnerability, there are known fixed releases available for Cisco bug IDs CSCut25292[“https://bst.cloudapps.cisco.com/bugsearch/bug/CSCut25292”] and CSCuw02037[“https://bst.cloudapps.cisco.com/bugsearch/bug/CSCuw02037”].