Cisco IP Phone 7800 Series and 8800 Series and Cisco Wireless IP Phone 8821 Denial of Service Vulnerability

A vulnerability in the Session Initiation Protocol (SIP) call-handling functionality of Cisco IP Phone 7800 Series, IP Phone 8800 Series, and Wireless IP Phone 8821 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected phone.

The vulnerability is due to incomplete input validation of SIP Session Description Protocol (SDP) parameters by the SDP parser of an affected phone. An attacker could exploit this vulnerability by sending a malformed SIP packet to an affected phone. A successful exploit could allow the attacker to cause all active phone calls on the affected phone to be dropped while the SIP process on the phone unexpectedly restarts, resulting in a DoS condition.

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-20180516-ip-phone-dos [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180516-ip-phone-dos”]