A vulnerability in the packet storing capabilities of Cisco 9900 Series IP Phones could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to how the phone decoder handles certain real-time transport protocol (RTP) packets. An attacker could exploit this vulnerability by calling a registered phone, waiting for a user to answer, then send malformed RTP packets to the user’s phone. A successful exploit could cause the phone to become unresponsive, resulting in a DoS condition. Cisco has confirmed the vulnerability and released software updates. To exploit this vulnerability, an attacker must first call a targeted phone and then rely on a user to answer the phone prior to sending malformed RTP packets. The attacker can not exploit this vulnerability without this requirement. Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
Version | Description | Section | Status | Date |
1.0 | Initial Release | NA | Final | 2015-Jun-29 |
THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.
A stand-alone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy, and may lack important information or contain factual errors. The information in this document is intended for end-users of Cisco products.