Cisco NX-OS Software Crafted Border Gateway Protocol Update Message Denial of Service Vulnerability

A vulnerability in the Border Gateway Protocol (BGP) functionality of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause all BGP sessions on the device to reset.

The vulnerability is due to the improper processing of specifically crafted BGP update messages. An attacker could exploit this vulnerability by crafting a specific BGP-labeled update message. An exploit could allow the attacker to cause all the BGP peers on a Cisco NX-OS device that are configured with either a VPNv4, VPNv6, or IPv6 labeled unicast address family to reset.

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

To exploit this vulnerability, it is likely that an attacker would need access to trusted, internal networks in order to send crafted BGP update messages to be processed by the targeted device. This access requirement may reduce the likelihood of a successful exploit.

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