Cisco IP Phone 8851 Session Initiation Protocol Denial of Service Vulnerability

A vulnerability in the Session Initiation Protocol (SIP) implementation of Cisco IP Phone 8851 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.

The vulnerability is due to an abnormal SIP message. An attacker could exploit this vulnerability by manipulating the CANCEL packet. An exploit could allow the attacker to cause a disruption of service to the phone.

There are no workarounds that address this vulnerability.

This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170517-sip [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170517-sip”]