Cisco Adaptive Security Appliance DHCPv6 Denial of Service Vulnerability

A vulnerability in the DHCP code of Cisco ASA Software could allow an unauthenticated, adjacent attacker to cause the reload of an affected system.

The vulnerability is due to insufficient validation of crafted or malformed DHCP version 6 (DHCPv6) packets when DHCPv6 replay feature is enabled. An attacker could exploit this vulnerability by sending a crafted DHCPv6 packet to the affected system.

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

Although an attacker does not need to authenticate to a targeted device to exploit this vulnerability, the attacker must have access to the same broadcast or collision domain of the device. This access requirement decreases 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.