cisco-sa-20190703-cucm-dos

A vulnerability in the Session Initiation Protocol (SIP) protocol implementation of Cisco Unified Communications Manager and Unified Communications Manager Session Management Edition could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient validation of input SIP traffic. An attacker could exploit this vulnerability by sending a malformed SIP packet to an affected Cisco Unified Communications Manager or Unified Communications Manager Session Management Edition. A successful exploit could allow the attacker to trigger a new registration process on all connected phones, temporarily disrupting service. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.