A vulnerability in Session Initiation Protocol (SIP) call handling of Cisco IP Phone 8800 Series devices could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition due to the SIP process unexpectedly restarting. All active phone calls are dropped as the SIP process restarts.
The vulnerability is due to incomplete input validation of the SIP packet header. An attacker could exploit this vulnerability by sending a malformed SIP packet to a targeted phone. An exploit could allow the attacker to cause a DoS condition when all phone calls are dropped, due to the SIP process unexpectedly restarting.
There are no workarounds that address this vulnerability.
This advisory is available at the following link: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170607-sip ["https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170607-sip"]