Cisco Unified IP Phone 9900 Series Mobility Extension Availability Vulnerability

A vulnerability in the mobility extension support of Cisco Unified IP Phone 9900 Series could allow an unauthenticated, remote attacker to log off the mobility extension user.

The vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending crafted packets to an affected device. An exploit could allow the attacker to cause a denial of service (DoS) condition in which the user is no longer associated with the device and
must log in again.

Cisco has confirmed the vulnerability in a security notice; however, software updates are not available.

To exploit this vulnerability, the attacker may need access to trusted, internal networks behind a firewall to send crafted packets to 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.