This vulnerability is addressed in the Cisco ATA 187 Analog Telephone Adaptor firmware version 184.108.40.206 ES build 4 or later.
When considering software upgrades, customers are advised to consult the Cisco Security Advisories and Responses archive at http://www.cisco.com/go/psirt and review subsequent advisories to determine exposure and a complete upgrade solution.
In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.
Currently there are no plans to publish any further releases of Cisco ATA 187 Analog Telephone Adaptor firmware to Cisco Software download section on Cisco.com.
Customers who require a fixed release, should contact their support organizations as described in the "Obtaining Fixed Software" section of this advisory.