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ESB-2007.0535 -- [Win][Linux] -- Cisco Unified Communications Manager and Presence Server Unauthorized Access Vulnerabilities

Date: 18 July 2007

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===========================================================================
             AUSCERT External Security Bulletin Redistribution

                       ESB-2007.0535 -- [Win][Linux]
         Cisco Unified Communications Manager and Presence Server
                    Unauthorized Access Vulnerabilities
                               18 July 2007

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:              Cisco Unified CallManager 5.0
                      Cisco Unified Communications Manager 5.1(2) and prior
                      Cisco Unified Presence Server 1.0(3) and prior
Publisher:            Cisco Systems
Operating System:     Windows
                      Linux variants
Impact:               Denial of Service
                      Inappropriate Access
Access:               Remote/Unauthenticated
CVE Names:            CVE-2007-3775 CVE-2007-3776

Original Bulletin:    

http://www.cisco.com/warp/public/707/cisco-sa-20070711-voip.shtml

- --------------------------BEGIN INCLUDED TEXT--------------------

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)
Please provide your feedback on this document.
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 ( registered customers only) - Unauthorized administrators can 
start/stop CUCM services

Calculate the environmental score of CSCsj09859

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 ( registered customers only) - Unauthorized administrators can 
start/stop CUPS services

Calculate the environmental score of CSCsj19985

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
Functional

CSCsj20668 ( registered customers only) - 
 Unauthorized administrators can view CUCM SNMP settings

Calculate the environmental score of CSCsj20668

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 ( registered customers only) - 
  Unauthorized administrators can view CUPS SNMP settings

Calculate the environmental score of CSCsj25962

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-cucm.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 Version - CUCM 5.0 & 5.1
Fixed Release - CUCM 5.1(2a)
Download Location

http://www.cisco.com/pcgi-bin/tablebuild.pl/callmgr-51?psrtdcat20e2

CUPS Version - CUPS 1.0
Fixed Release - CUPS 6.0(1) *
Download Location

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 1.0 - 2007-July-11

Initial 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. 
- --------------------------END INCLUDED TEXT--------------------

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===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
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===========================================================================

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