Intellishield has updated this alert to add the specific Cisco Unified IP phone series that are affected by the crafted SDP packet vulnerability.
A vulnerability in the SDP negotiation logic of the Cisco Cisco Unified IP Phone 9951, Cisco Unified IP Phone 9971 and the Cisco Unified IP Phone 8961 could allow an unauthenticated, remote attacker to cause the phone to reboot.
The vulnerability is due to improper processing of crafted SDP packets. An attacker could exploit this vulnerability by sending crafted SDP packets to the phone to cause the phone to reload.
Cisco has confirmed the vulnerability in a security notice; however, software updates are not available.
At the time this alert was first published, Cisco Unified IP Phones 9900 Series Firmware versions 9.3.2 SR1 and prior were vulnerable. Later releases of Cisco Unified IP Phones 9900 Series Firmware may also be vulnerable.
To exploit this vulnerability, an attacker must be able to send crafted SDP packets to the targeted device, which may reside on trusted, internal networks that the attacker may need access to. This access requirement decreases the likelihood of a successful exploit.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
Cisco has released a security notice at the following link: CVE-2013-5526
Customers are advised to consult Cisco bug ID CSCuf06698 for the most complete list of affected product versions.
An unauthenticated, remote attacker could exploit this vulnerability to cause an affected device to reload, resulting in a DoS condition.
The vulnerability is due to to improper processing of crafted SDP packets by an affected device running the vulnerable firmware versions.
An unauthenticated, remote attacker could exploit this vulnerability by sending crafted SDP packets to an affected device. Successful exploitation could cause the targeted device to reload, resulting in a DoS condition.
Administrators are advised to contact the vendor regarding future updates and releases.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to monitor affected systems.
Software updates are not available.
Version 1, October 10, 2013, 5:32 PM: Cisco fourth-generation RT style IP phones contain a vulnerability to could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are not available.
The urgency and severity ratings of this alert are not tailored to individual users; users may value alerts differently based upon their network configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.