|
Brought to you by:
Suppliers of:
|
|
|
| |
Several vulnerabilities have been identified and repaired in Cisco IP Phones. One vulnerability allows unauthorized modification of the phone's configuration, while the remainders cause the phone to restart when certain types of network traffic are received.
Workarounds are available for some of the vulnerabilities. Cisco is offering free fixed software to address these vulnerabilities. Full details are available below and in the on-line copy of this document at http://www.cisco.com/warp/public/707/multiple-ip-phone-vulnerabilities-pub.shtml. |
| |
Credit:
The information has been provided by Cisco Systems Product Security Incident Response Team.
|
| |
Affected Products:
Cisco IP Phone models 7910, 7940, and 7960 are the only Cisco products affected by these vulnerabilities.
Details:
CSCdw16714
CSCdw16720
CSCdw95128
CSCdv29136
The Cisco IP Phones are vulnerable to several network based Denial of Service (DoS) attacks including the well-known attacks for "jolt", "jolt2", "raped", "hping2", "bloop", "bubonic", "mutant", "trash", and "trash2". All of these defects were resolved by improving the ability of the IP Phone to resist high rates of traffic directed at the IP Phone.
CSCdw93296
CSCdx21102
The Cisco IP phones include a built-in web server on port 80. The server provides several pages of debug and status information about the phone. It is possible to modify an HTTP request to exploit an input validation vulnerability that results in the re-initialization of the IP phone.
CSCdx21108
The Cisco IP Phones store their configuration information locally and most of it is accessible through the "Settings" button on the phone. By default, these settings are locked (as indicated by a padlock icon in the mode title bar when viewing them) to prevent them from being changed accidentally. These settings may be modified via a trusted path key combination: '**#'. This is documented in the product manual and is not admin-configurable. Once unlocked, several fields can be reconfigured. Modification of the phone's configuration is very likely to go unnoticed, since a user never has to interact with the configuration menu where these changes were made. This will be resolved later by a configuration option to control the ability to make local configuration changes at the keypad of the phone.
Impact:
Cisco IP Phones can be forced to restart by an attacker using any of a variety of widely available, well-known DOS programs if the attacker can successfully transmit packets to the IP Telephone. The phone may also restart in the event it receives a crafted HTTP request with invalid arguments directed at the phone. Any call in progress on the affected IP Phone will be disconnected, and the IP Phone will not be useable until it has finished restarting and resumed normal operation. This attack can be repeated indefinitely.
Cisco IP phones running a SIP or MGCP image are subject to the same widely available denial-of-service programs but are not susceptible to a web-based attack as those images do not include a web interface.
Normal operation of Cisco IP Phones can be subverted if an attacker obtains local physical access to the IP Phone and reconfigures it, possibly forcing it to download software or configuration information of his or her own choosing. A successful attacker could gain full control over the operation of the IP Phone and any call setup requests and responses made between the IP Phone and Cisco CallManagers or other VoIP gateways.
Software Versions and Fixes:
Cisco IP Phone Firmware (fixes carry forward into all later versions)
CallManager Version Affected - First Fixed Firmware Release - First Fixed CallManager Release.
3.0 - P003J310 - N/A
3.1 - P00303010401- 3.1(4)
3.2 - P00303020203 (available 2002-05-29) - TBD
Cisco IP Phone SIP or MGCP Firmware (fixes carry forward into all later versions)
Version Affected - First Fixed Firmware Release.
POS3-03-1-00 and earlier - TBD
POM3-03-1-00 and earlier - TBD
Obtaining Fixed Software
Cisco is offering free software upgrades to address this vulnerability for all affected customers. Customers may only install and expect support for the feature sets they have purchased.
Customers with service contracts should contact their regular update channels to obtain any software release containing the feature sets they have purchased. For most customers with service contracts, this means that upgrades should be obtained through the Software Center on Cisco's Worldwide Web site at http://www.cisco.com/.
Customers whose Cisco products are provided or maintained through a prior or existing agreement with third-party support organizations such as Cisco Partners, authorized resellers, or service providers should contact that support organization for assistance with obtaining the free software upgrade(s).
Customers who purchased directly from Cisco but who do not hold a Cisco service contract, and customers who purchase through third party vendors but are unsuccessful at obtaining fixed software through their point of sale, should obtain fixed software by contacting the Cisco Technical Assistance Center (TAC) using the contact information listed below. In these cases, customers are entitled to obtain an upgrade to a later version of the same release or as indicated by the applicable row in the Software Versions and Fixes table (noted above).
Cisco TAC contacts are as follows:
* +1 800 553 2447 (toll free from within North America)
* +1 408 526 7209 (toll call from anywhere in the world)
* e-mail: tac@cisco.com
See http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml for additional TAC contact information, including special localized telephone numbers, instructions, and e-mail addresses for use in various languages.
Please have your product serial number available and give the URL of this notice as evidence of your entitlement to a free upgrade.
Please do not contact either "psirt@cisco.com" or "security-alert@cisco.com" for software upgrades.
Workarounds:
Denial-of-service attacks on the Cisco IP Phone can be mitigated by limiting or blocking IP traffic from untrusted sources. Exploitation of the web interface vulnerability can be provided by blocking access to port 80 via other devices on the network. The basic configuration of the Cisco IP Telephone can be protected by permitting physical access only by authorized users and network administrators.
|
|
|
|
|
