[c-nsp] Cisco Security Advisory: Cisco Unified Communications Manager Denial of Service and Authentication Bypass Vulnerabilities

Wed Jun 25 12:00:00 EDT 2008

Cisco Unified Communications Manager (CUCM), formerly Cisco
CallManager, contains a denial of service (DoS) vulnerability in the
Computer Telephony Integration (CTI) Manager service that may cause
an interruption in voice services and an authentication bypass
vulnerability in the Real-Time Information Server (RIS) Data
Collector that may expose information that is useful for
reconnaissance.

Cisco has released free software updates that address these
vulnerabilities. There are no workarounds for these vulnerabilities.

This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20080625-cucm.shtml.

Affected Products
=================

Vulnerable Products
+------------------

The following products are vulnerable:

  * Cisco Unified CallManager 4.1 versions
  * Cisco Unified Communications Manager 4.2 versions prior to 4.2(3)SR4
  * Cisco Unified Communications Manager 4.3 versions prior to 4.3(2)SR1
  * Cisco Unified Communications Manager 5.x versions prior to 5.1(3c)
  * Cisco Unified Communications Manager 6.x versions prior to 6.1(2)

Administrators of systems running Cisco Unified Communications
Manager (CUCM) version 4.x can determine the software version by
navigating to Help > About Cisco Unified CallManager and selecting
the Details button via the CUCM administration interface.

Administrators of systems that are running CUCM versions 5.x and 6.x
can determine the software version by viewing the main page of the
CUCM administration interface. The software version can also be
determined by running the command show version active via the command
line interface (CLI).

Products Confirmed Not Vulnerable
+--------------------------------

Cisco Unified Communications Manager Express is not affected by these
vulnerabilities. No other Cisco products are currently known to be
affected by these vulnerabilities.

Details
=======

Cisco Unified Communications Manager (CUCM) is the call processing
component of the Cisco IP Telephony solution that extends enterprise
telephony features and functions to packet telephony network devices,
such as IP phones, media processing devices, VoIP gateways, and
multimedia applications.

Computer Telephony Integration Manager Related Vulnerability

The Computer Telephony Integration (CTI) Manager service of CUCM
versions 5.x and 6.x contains a vulnerability when handling malformed
input that may result in a DoS condition. The CTI Manager service
listens by default on TCP port 2748 and is not user-configurable.
There is no workaround for this vulnerability. This vulnerability is
fixed in CUCM versions 5.1(3c) and 6.1(2). This vulnerability is
documented in Cisco Bug ID CSCso75027 and has been assigned Common
Vulnerabilities and Exposures (CVE) identifier CVE-2008-2061.

Real-Time Information Server Data Collector Related Vulnerability

The Real-Time Information Server (RIS) Data Collector service of CUCM
versions 4.x, 5.x, and 6.x contains an authentication bypass
vulnerability that may result in the unauthorized disclosure of
certain CUCM cluster information. In normal operation, Real-Time
Monitoring Tool (RTMT) clients gather CUCM cluster statistics by
authenticating to a Simple Object Access Protocol (SOAP) based web
interface. The SOAP interface proxies authenticated connections to
the RIS Data Collector process. The RIS Data Collector service
listens on TCP port 2556 by default and is user configurable. By
connecting directly to the port that the RIS Data Collector process
listens on, it may be possible to bypass authentication checks and
gain read-only access to information about a CUCM cluster. The
information available includes performance statistics, user names,
and configured IP phones. This information may be used to mount
further attacks. No passwords or other sensitive CUCM configuration
may be obtained via this vulnerability. No CUCM configuration changes
can be made.

There is no workaround for this vulnerability. This vulnerability is
fixed in CUCM versions 4.2(3)SR4, 4.3(2)SR1, 5.1(3), and 6.1(1). For
CUCM 4.x versions, this vulnerability is documented in Cisco Bug ID
CSCsq35151 and has been assigned CVE identifier CVE-2008-2062. For
CUCM 5.x and 6.x versions, this vulnerability is documented in Cisco
Bug ID CSCsj90843 and has been assigned CVE identifier CVE-2008-2730.

Vulnerability Scoring Details
=============================

Cisco has provided scores for the vulnerabilities in this advisory
based on the Common Vulnerability Scoring System (CVSS). The CVSS
scoring in this Security Advisory is done in accordance with CVSS
version 2.0.

CVSS is a standards-based scoring method that conveys vulnerability
severity and helps determine urgency and priority of response.

Cisco has provided a base and temporal score. Customers can then
compute environmental scores to assist in determining the impact of
the vulnerability in individual networks.

Cisco has provided an FAQ to answer additional questions regarding
CVSS at:

http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html

Cisco has also provided a CVSS calculator to help compute the
environmental impact for individual networks at:

http://intellishield.cisco.com/security/alertmanager/cvss

CSCso75027 - CTI Manager TSP Crash

CVSS Base Score - 7.8
    Access Vector - Network
    Access Complexity - Low
    Authentication - None
    Confidentiality Impact - None
    Integrity Impact - None
    Availability Impact - Complete

CVSS Temporal Score - 6.4
    Exploitability - Functional
    Remediation Level - Official Fix
    Report Confidence - Confirmed

CSCsq35151 - RISDC Authentication Bypass

CVSS Base Score - 5
    Access Vector - Network
    Access Complexity - Low
    Authentication - None
    Confidentiality Impact - Partial
    Integrity Impact - None
    Availability Impact - None

CVSS Temporal Score - 4.1
    Exploitability - Functional
    Remediation Level - Official Fix
    Report Confidence - Confirmed

CSCsj90843 - RISDC Authentication Bypass

CVSS Base Score - 5
    Access Vector - Network
    Access Complexity - Low
    Authentication - None
    Confidentiality Impact - Partial
    Integrity Impact - None
    Availability Impact - None

CVSS Temporal Score - 4.1
    Exploitability - Functional
    Remediation Level - Official Fix
    Report Confidence - Confirmed

Impact
======

Successful exploitation of the vulnerabilities in this advisory may
result in the interruption of voice services or disclosure of
information useful for reconnaissance.

Software Versions and Fixes
===========================

When considering software upgrades, also consult http://www.cisco.com/go/psirt
and any subsequent advisories to determine exposure and a
complete upgrade solution.

In all cases, customers should exercise caution to be certain the
devices to be upgraded contain sufficient memory and that current
hardware and software configurations will continue to be supported
properly by the new release. If the information is not clear, contact
the Cisco Technical Assistance Center (TAC) or your contracted
maintenance provider for assistance.

Cisco Unified Communications Manager (CUCM) version 4.2(3)SR4
contains fixes for all vulnerabilities affecting CUCM version 4.2
listed in this advisory. Cisco Unified CallManager 4.1 version
administrators are encouraged to upgrade to CUCM version 4.2(3)SR4 in
order to obtain fixed software. Version 4.2(3)SR4 can be downloaded
at the following link:

http://tools.cisco.com/support/downloads/go/PlatformList.x?sftType=Unified%20Communications%20Manager%20Updates&mdfid=280264388&treeName=Voice%20and%20Unified%20Communications&mdfLevel=Software%20Version/Option&url=null&modelName=Cisco%20Unified%20CallManager%20Version%204.2&isPlatform=N&treeMdfId=278875240&modifmdid=null&imname=null&hybrid=Y&imst=N

CUCM version 4.3(2)SR1 contains fixes for all vulnerabilities
affecting CUCM version 4.3 listed in this advisory and is scheduled
to be released in mid-July, 2008. Version 4.3(2)SR1 will be available
for download at the following link:

http://tools.cisco.com/support/downloads/go/PlatformList.x?sftType=Unified%20Communications%20Manager%20Updates&mdfid=280771554&treeName=Voice%20and%20Unified%20Communications&mdfLevel=Software%20Version/Option&url=null&modelName=Cisco%20Unified%20Communications%20Manager%20Version%204.3&isPlatform=N&treeMdfId=278875240&modifmdfid=null&imname=null&hybrid=Y&imst=N

CUCM version 5.1(3c) contains fixes for all vulnerabilities affecting
CUCM version 5.x listed in this advisory. Version 5.1(3c) can
downloaded at the following link:

http://tools.cisco.com/support/downloads/go/ReleaseType.x?optPlat=null&isPlatform=Y&mdfid=280735907&sftType=Unified%20Communications%20Manager%20Updates&treeName=Voice%20and%20Unified%20Communications&modelName=Cisco%20Unified%20Communications%20Manager%20Version%205.1&mdfLevel=Software%20Version/Option&treeMdfId=278875240&modifmdfid=null&imname=null&hybrid=Y&imst=N

CUCM version 6.1(2) contains fixes for all vulnerabilities affecting
CUCM version 6.x listed in this advisory. Version 6.1(2) can be
downloaded at the following link:

http://tools.cisco.com/support/downloads/go/PlatformList.x?sftType=Unified%20Communications%20Manager%20Updates&mdfid=281023410&treeName=Voice%20and%20Unified%20Communications&mdfLevel=Software%20Version/Option&url=null&modelName=Cisco%20Unified%20Communications%20Manager%20Version%206.1&isPlatform=N&treeMdfId=278875240&modifmdfid=null&imname=null&hybrid=Y&imst=N

Workarounds
===========

CTI Manager Related Vulnerability

It is possible to mitigate the CTI Manager vulnerability (CSCso75027)
by implementing filtering on screening devices. Administrators are
advised to permit access to TCP port 2748 only from networks that
contain systems running CTI-enabled applications.

RIS Data Collector Related Vulnerability

It is possible to mitigate the RIS Data Collector vulnerability
(CSCsq35151 and CSCsj90843) by implementing filtering on screening
devices. Administrators are advised to permit access to TCP port 2556
only from other CUCM cluster systems.

It is possible to change the default port (TCP 2556) of the RIS Data
Collector service. If changed, filtering should be based on the
values used. The values of the ports can be viewed in the Cisco
Unified Communications Manager (CUCM) administration interface by
following the System > Service Parameters menu and selecting the
appropriate service.

Additional mitigation techniques that can be deployed on Cisco
devices within the network are available in the Cisco Applied
Mitigation Bulletin companion document for this advisory:

http://www.cisco.com/warp/public/707/cisco-amb-20080625-cucm.shtml

Obtaining Fixed Software
========================

Cisco has released free software updates that address these
vulnerabilities. Prior to deploying software, customers should
consult their maintenance provider or check the software for feature
set compatibility and known issues specific to their environment.

Customers may only install and expect support for the feature sets
they have purchased. By installing, downloading, accessing or
otherwise using such software upgrades, customers agree to be bound
by the terms of Cisco's software license terms found at
http://www.cisco.com/en/US/products/prod_warranties_item09186a008088e31f.html,
or as otherwise set forth at Cisco.com Downloads at
http://www.cisco.com/public/sw-center/sw-usingswc.shtml.

Do not contact psirt at cisco.com or security-alert at cisco.com for
software upgrades.

Customers with Service Contracts
+-------------------------------

Customers with contracts should obtain upgraded software through
their regular update channels. For most customers, this means that
upgrades should be obtained through the Software Center on Cisco's
worldwide website at http://www.cisco.com.

Customers using Third Party Support Organizations
+------------------------------------------------

Customers whose Cisco products are provided or maintained through
prior or existing agreements with third-party support organizations,
such as Cisco Partners, authorized resellers, or service providers
should contact that support organization for guidance and assistance
with the appropriate course of action in regards to this advisory.

The effectiveness of any workaround or fix is dependent on specific
customer situations, such as product mix, network topology, traffic
behavior, and organizational mission. Due to the variety of affected
products and releases, customers should consult with their service
provider or support organization to ensure any applied workaround or
fix is the most appropriate for use in the intended network before it
is deployed.

Customers without Service Contracts
+----------------------------------

Customers who purchase direct from Cisco but do not hold a Cisco
service contract, and customers who purchase through third-party
vendors but are unsuccessful in obtaining fixed software through
their point of sale should acquire upgrades by contacting the Cisco
Technical Assistance Center (TAC). 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 at cisco.com

Customers should have their product serial number available and be
prepared to give the URL of this notice as evidence of entitlement to
a free upgrade. Free upgrades for non-contract customers must be
requested through the TAC.

Refer to http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml
for additional TAC contact information, including localized telephone
numbers, and instructions and e-mail addresses for use in various
languages.

Exploitation and Public Announcements
=====================================

The Cisco PSIRT is not aware of any public announcements or malicious
use of the vulnerability described in this advisory.

Cisco PSIRT greatly appreciates the opportunity to work with
researchers on security vulnerabilities and welcomes the opportunity
to review and assist in product reports. We would like to thank
VoIPshield for working with us towards the goal of keeping Cisco
networks and the Internet, as a whole, secure.

Status of this Notice: FINAL

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 in the following section is an
uncontrolled copy, and may lack important information or contain
factual errors.

Distribution
============

This advisory is posted on Cisco's worldwide website at :

http://www.cisco.com/warp/public/707/cisco-sa-20080625-cucm.shtml

In addition to worldwide web posting, a text version of this notice
is clear-signed with the Cisco PSIRT PGP key and is posted to the
following e-mail and Usenet news recipients.

  * cust-security-announce at cisco.com
  * first-teams at first.org
  * bugtraq at securityfocus.com
  * vulnwatch at vulnwatch.org
  * cisco at spot.colorado.edu
  * cisco-nsp at puck.nether.net
  * full-disclosure at lists.grok.org.uk
  * comp.dcom.sys.cisco at newsgate.cisco.com

Future updates of this advisory, if any, will be placed on Cisco's
worldwide website, but may or may not be actively announced on
mailing lists or newsgroups. Users concerned about this problem are
encouraged to check the above URL for any updates.

Revision History
================

+---------------------------------------+
| Revision |              | Initial     |
| 1.0      | 2008-June-25 | public      |
|          |              | release     |
+---------------------------------------+

Cisco Security Procedures
=========================

Complete information on reporting security vulnerabilities in Cisco
products, obtaining assistance with security incidents, and
registering to receive security information from Cisco, is available
on Cisco's worldwide website at http://www.cisco.com/en/US/products/
products_security_vulnerability_policy.html. This includes
instructions for press inquiries regarding Cisco security notices.
All Cisco security advisories are available at http://www.cisco.com/
go/psirt.
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