Cisco Network Registrar DHCPv6 Denial of Service Vulnerability

A vulnerability in the DHCPv6 server module of Cisco Network Registrar could allow an unauthenticated, remote attacker to cause a reload of the DHCPv6 server on an affected device.

The vulnerability is due to the way certain malformed requests are processed. An attacker could exploit this vulnerability by sending a malformed DHCPv6 packet to an affected device. A successful exploit could allow the attacker to cause a reload of the DHCPv6 server, which could result in a denial of service condition.

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

To exploit this vulnerability, an attacker may need access to trusted, internal networks to send malformed DHCPv6 packets to a targeted device. This access requirement decreases the possibility 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.