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Cisco Security Advisory: Cisco Unified Communications Manager and
Presence Server Unauthorized Access Vulnerabilities
Document ID: 97060
Advisory ID: cisco-sa-20070711-voip
http://www.cisco.com/warp/public/707/cisco-sa-20070711-voip.shtml
Revision 1.0
For Public Release 2007 July 11 1600 UTC (GMT)
- ---------------------------------------------------------------------
Contents
=======
Summary
Affected Products
Details
Vulnerability Scoring Details
Impact
Software Version and Fixes
Workarounds
Obtaining Fixed Software
Exploitation and Public Announcements
Status of this Notice: FINAL
Distribution
Revision History
Cisco Security Procedures
- ---------------------------------------------------------------------
Summary
======
Cisco Unified Communications Manager (CUCM), formerly CallManager,
and Cisco Unified Presence Server (CUPS) contain two vulnerabilities
that could allow an unauthorized administrator to activate and
terminate CUCM / CUPS system services and access SNMP configuration
information. This may respectively result in a denial of service
(DoS) condition affecting CUCM/CUPS cluster systems and the
disclosure of sensitive SNMP details, including community strings.
There are no workarounds for these vulnerabilities.
Cisco has made free software available to address these
vulnerabilities for affected customers.
This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20070711-voip.shtml
Affected Products
================
Note: Cisco Unified CallManager versions 4.2, 4.3, 5.1 and 6.0 have
been renamed as Cisco Unified Communications Manager. CUCM versions
3.3, 4.0, 4.1 and 5.0 retain the Cisco Unified CallManager name.
Vulnerable Products
+------------------
These products are vulnerable:
* Cisco Unified CallManager 5.0 and Communications Manager 5.1
versions up to and including 5.1(2)
* Cisco Unified Presence Server 1.0 versions up to and including
1.0(3)
Administrators of systems running CUCM version 5.x and CUPS version
1.x can determine the software version by viewing the main page of
the CUCM/CUPS 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 CallManager versions 3.3, 4.0, 4.1, 4.2
* Cisco Unified Communications Manager versions 4.3, 6.0
* Cisco Unified Presence Server version 6.0
No other Cisco products are currently known to be affected by these
vulnerabilities.
Details
======
* Unauthorized Administrator Can Activate/Terminate CUCM/CUPS
System Services
An unauthorized CUCM/CUPS administrator may be able to activate
and terminate system services in a CUCM/CUPS cluster environment.
This may result in a denial of critical voice services. The
unauthorized administrator cannot make changes to or view the
configuration of the vulnerable CUCM/CUPS system, with the
exception of viewing SNMP settings, which is documented in the
next vulnerability. The CUCM issue is documented by Cisco Bug ID
CSCsj09859. The CUPS issue is documented by Cisco Bug ID
CSCsj19985.
* Unauthorized Administrator Can View CUCM/CUPS SNMP Settings
An unauthorized CUCM/CUPS administrator may be able to view
sensitive SNMP configuration information in a CUCM/CUPS cluster
environment. This may result in the disclosure of sensitive
information, including SNMP community strings. The CUCM issue is
documented in Cisco Bug ID CSCsj20668. The CUPS issue is
documented in Cisco Bug ID CSCsj25962.
Vulnerability Scoring Details
============================
Cisco is providing 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 1.0.
Cisco will provide a base and temporal score. Customers can then
compute environmental scores to assist in determining the impact of
the vulnerability in individual networks.
Cisco PSIRT will set the bias in all cases to normal. Customers are
encouraged to apply the bias parameter when determining the
environmental impact of a particular vulnerability.
CVSS is a standards based scoring method that conveys vulnerability
severity and helps determine urgency and priority of response.
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
CSCsj09859 - Unauthorized administrators can start/stop CUCM services
CVSS Base Score - 7
Access Vector - Remote
Access Complexity - Low
Authentication - Not Required
Confidentiality Impact - Partial
Integrity Impact - Partial
Availability Impact - Partial
Impact Bias - Normal
CVSS Temporal Score - 5.8
Exploitability - Functional
Remediation Level - Official-Fix
Report Confidence - Confirmed
CSCsj19985 - Unauthorized administrators can start/stop CUPS services
CVSS Base Score - 7
Access Vector - Remote
Access Complexity - Low
Authentication - Not Required
Confidentiality Impact - Partial
Integrity Impact - Partial
Availability Impact - Partial
Impact Bias - Normal
CVSS Temporal Score - 5.8
Exploitability - Functional
Remediation Level - Official-Fix
Report Confidence - Confirmed
CSCsj20668 - Unauthorized administrators can view CUCM SNMP settings
CVSS Base Score - 2.3
Access Vector - Remote
Access Complexity - Low
Authentication - Not Required
Confidentiality Impact - Partial
Integrity Impact - None
Availability Impact - None
Impact Bias - Normal
CVSS Temporal Score - 1.9
Exploitability - Functional
Remediation Level - Official-Fix
Report Confidence - Confirmed
CSCsj25962 - Unauthorized administrators can view CUPS SNMP settings
CVSS Base Score - 2.3
Access Vector - Remote
Access Complexity - Low
Authentication - Not Required
Confidentiality Impact - Partial
Integrity Impact - None
Availability Impact - None
Impact Bias - Normal
CVSS Temporal Score - 1.9
Exploitability - Functional
Remediation Level - Official-Fix
Report Confidence - Confirmed
Impact
====
Successful exploitation of the service activation/termination
vulnerability may result in a DoS condition affecting critical voice
services. An attacker could disable central CUCM services,
effectively causing the complete disruption of a CUCM cluster.
Successful exploitation of the SNMP settings vulnerability may result
in the disclosure of sensitive network configuration information,
including SNMP community strings. Using this information, an attacker
may be able to leverage access to sensitive information on other
systems in the network. It is a common practice in many enterprise
environments to utilize standardized SNMP community strings. This may
compound the severity of this vulnerability.
Software Version 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.
Workarounds
==========
There are no workarounds for these vulnerabilities. It is possible to
mitigate these vulnerabilities by permitting only trusted CUCM/CUPS
cluster nodes and administrator workstations to access TCP port 8443
on a vulnerable CUCM/CUPS system.
Although it is often difficult to block traffic transiting your
network, it is possible to identify traffic which should never be
allowed to target your infrastructure devices and block that traffic
at the border of your network. Infrastructure ACLs are considered a
network security best practice and should be considered as a
long-term addition to good network security, as well as a workaround
for this specific vulnerability. The filters shown above should be
included as part of an infrastructure access list, which will protect
all devices with IP addresses in the infrastructure IP address range.
The white paper entitled "Protecting Your Core: Infrastructure
Protection Access Control Lists" presents guidelines and recommended
deployment techniques for infrastructure protection access lists.
This document is available at the following link:
http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a00801a1a55.shtml
Filters blocking access to TCP/8443 should be deployed at the network
edge as part of a transit access list that will protect the router
where the ACL is configured, as well as other devices behind it.
Further information about transit ACLs is available in the white
paper "Transit Access Control Lists: Filtering at Your Edge," which
is available at the following link:
http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a00801afc76.shtml
Additional mitigations that can be deployed on Cisco devices within
the network are available in the Cisco Applied Intelligence companion
document for this advisory:
http://www.cisco.com/warp/public/707/cisco-air-20070711-voip.shtml
Obtaining Fixed Software
=======================
Cisco will make free software available to address this vulnerability
for affected customers. This advisory will be updated as fixed
software becomes available. 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/public/sw-license-agreement.html, or as otherwise
set forth at Cisco.com Downloads at
http://www.cisco.com/public/sw-center/sw-usingswc.shtml
Do not contact either "psirt@cisco.com" or "security-alert@cisco.com"
for software upgrades.
CUCM 5.0 & 5.1 - First Fixed Release is CUCM 5.1(2a), download link:
http://www.cisco.com/pcgi-bin/tablebuild.pl/callmgr-51?psrtdcat20e2
CUPS 1.0 - First Fixed Release is CUPS 6.0(1) * download link:
http://www.cisco.com/pcgi-bin/tablebuild.pl/cups-60?psrtdcat20e2
* Development of CUPS version 1.0 is discontinued. Users should
upgrade to CUPS version 6.0 to obtain fixes for these
vulnerabilities.
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 agreement 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 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 get their 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@cisco.com
Have your product serial number available and give the URL of this
notice as evidence of your 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 special 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.
These vulnerabilities were discovered internally by Cisco.
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-20070711-voip.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@cisco.com
* first-teams@first.org
* bugtraq@securityfocus.com
* vulnwatch@vulnwatch.org
* cisco@spot.colorado.edu
* cisco-nsp@puck.nether.net
* full-disclosure@lists.grok.org.uk
* comp.dcom.sys.cisco@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 | 2007-July-11 | 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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