Cisco Headend System Release UDP TFTP and DHCP Denial of Service Vulnerability

A vulnerability in the UDP applications TFTP and DHCP of Cisco Headend System Release could allow an unauthenticated, remote attacker to take the TFTP and DHCP listening ports offline for a period of time.

The vulnerability is due to a particular UDP traffic pattern in addition to the amount of UDP traffic generated. An attacker could exploit this vulnerability by sending crafted UDP packets for TFTP and DHCP to the device. An exploit could allow the attacker to take the TFTP and DHCP ports offline so those ports do not respond to incoming requests, resulting in a denial of service (DoS) condition.

Cisco has confirmed the vulnerability; however, software updates are not available.

To exploit this vulnerability, an attacker may need access to trusted, internal networks to send crafted UDP packets for TFTP and DHCP to the affected 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.