A vulnerability in edge devices of the Cisco Unified Communications Manager using Mobile and Remote Access (MRA) services could allow an unauthenticated, remote attacker to perform an identity theft attack.
The vulnerability is due to improper identity validation of the edge devices. An attacker could exploit this vulnerability by spoofing a user’s identity and taking ownership of the edge device. A successful exploit will allow the attacker to setup and receive voice calls acting as the registered user of the device.
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
This advisory is available at the following link: http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20151209-ucm