Products & Services
Support

Product Categories


Popular Downloads


Manage Software

How to Buy

For Home

Linksys Products Store
Linksys is now part of Belkin
Products for everyone

All Ordering Options

Training & Events Partners
Guest

Cisco Security Advisory

Cisco Unified Communications Manager Express Vulnerability

Advisory ID: cisco-sa-20090923-cme

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20090923-cme

Revision 1.1

For Public Release 2009 September 23 16:00  UTC (GMT)


Summary

Cisco IOS® devices that are configured for Cisco Unified Communications Manager Express (CME) and the Extension Mobility feature are vulnerable to a buffer overflow vulnerability. Successful exploitation of this vulnerability may result in the execution of arbitrary code or a Denial of Service (DoS) condition on an affected device.

Cisco has released free software updates that address this vulnerability.

This advisory is posted at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20090923-cme.

Note: The September 23, 2009, Cisco IOS Security Advisory bundled publication includes eleven Security Advisories. Ten of the advisories address vulnerabilities in Cisco IOS Software, and one advisory addresses a vulnerability in Cisco Unified Communications Manager. Each advisory lists the releases that correct the vulnerability or vulnerabilities detailed in the advisory.

Individual publication links are in "Cisco Event Response: Semiannual Cisco IOS Software Advisory Bundled Publication" at the following link:

http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_sep09.html

Affected Products

Cisco IOS devices, including Cisco Unified Communications 500 Series, that are configured for Cisco Unified CME and the Extension Mobility feature are affected.

Vulnerable Products

A Cisco IOS device that is configured for Cisco Unified CME and Extension Mobility contains the following output when the show running-config command is issued:

ephone [Ethernet phone tag]
  ...
  logout-profile [logout-profile tag]

To determine the Cisco IOS Software release that is running on a Cisco product, administrators can log in to the device and issue the show version command to display the system banner. The system banner confirms that the device is running Cisco IOS Software by displaying text similar to "Cisco Internetwork Operating System Software" or "Cisco IOS Software." The image name is displayed in parentheses, followed by "Version" and the Cisco IOS Software release name. Other Cisco devices do not have the show version command or may provide different output.

The following example identifies a Cisco product that is running Cisco IOS Software Release 12.3(26) with an installed image name of C2500-IS-L:

    Router#show version
    Cisco Internetwork Operating System Software
    IOS (tm) 2500 Software (C2500-IS-L), Version 12.3(26), RELEASE SOFTWARE (fc2)
    Technical Support: http://www.cisco.com/techsupport
    Copyright (c) 1986-2008 by cisco Systems, Inc.
    Compiled Mon 17-Mar-08 14:39 by dchih

    <output truncated>

The following example identifies a Cisco product that is running Cisco IOS Software Release 12.4(20)T with an installed image name of C1841-ADVENTERPRISEK9-M:

    Router#show version
    Cisco IOS Software, 1841 Software (C1841-ADVENTERPRISEK9-M), Version 12.4(20)T, RELEASE SOFTWARE (fc3)
    Technical Support: http://www.cisco.com/techsupport
    Copyright (c) 1986-2008 by Cisco Systems, Inc.
    Compiled Thu 10-Jul-08 20:25 by prod_rel_team

    <output truncated>

Additional information about Cisco IOS Software release naming conventions is available in "White Paper: Cisco IOS Reference Guide" at the following link: http://www.cisco.com/warp/public/620/1.html .

Products Confirmed Not Vulnerable

Cisco IOS devices that are configured for Survivable Remote Site Telephony (SRST) Mode are not affected.

Cisco IOS XR is not affected.

Cisco IOS XE is not affected.

Cisco Unified Communications Manager is not affected.

Cisco Unified CME is not affected unless configured to use the Extension Mobility feature.

No other Cisco products are currently known to be affected by these vulnerabilities.

Details

Cisco Unified CME is the call processing component of an enhanced IP telephony solution that is integrated into Cisco IOS.

The Extension Mobility feature in Cisco Unified CME provides the benefit of phone mobility for end users. A user login service allows phone users to temporarily access a physical phone other than their own phone and utilize their personal settings, such as directory number, speed-dial lists, and services, that is assigned to their own desk phone. The phone user can make and receive calls on that phone using the same personal directory number as is on their own desk phone. More information on Extension Mobility feature is available at the following URL:

http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/admin/configuration/guide/cmemobl.html

A vulnerability in the login section of the Extension Mobility feature may allow an unauthenticated attacker to execute arbitrary code or cause a Denial of Service (DoS) condition. Such packets can only come from registered phone IP addresses in the form of HTTP requests. If the auto-registration feature is enabled, an attacker can register its IP address and subsequently send a crafted payload to exploit this vulnerability. The auto-registration feature is enabled by default. More information on auto-registration can be found at the following link:

http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/command/reference/cme_a1ht.html#wp1031242.

This vulnerability is addressed by the Cisco Bug ID CSCsq58779 ( registered customers only) and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2009-2865.

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 .

CSCsq58779 - Vulnerability in Extension Mobility Feature

Calculate the environmental score of Calculate the environmental score of Bug ID CVSS scoring link

CVSS Base Score - 7.6

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

High

None

Complete

Complete

Complete

CVSS Temporal Score - 6.3

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed

Impact

Successful exploitation of this vulnerability may result in the execution of arbitrary code or a Denial of Service (DoS) condition on an affected device.

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.

Each row of the Cisco IOS software table (below) names a Cisco IOS release train. If a given release train is vulnerable, then the earliest possible releases that contain the fix (along with the anticipated date of availability for each, if applicable) are listed in the "First Fixed Release" column of the table. The "Recommended Release" column indicates the releases which have fixes for all the published vulnerabilities at the time of this Advisory. A device running a release in the given train that is earlier than the release in a specific column (less than the First Fixed Release) is known to be vulnerable. Cisco recommends upgrading to a release equal to or later than the release in the "Recommended Releases" column of the table.

Major Release

     Availability of Repaired Releases

Affected 12.0-Based Releases

First Fixed Release

Recommended Release

There are no affected 12.0 based releases.

Affected 12.1-Based Releases

First Fixed Release

Recommended Release

There are no affected 12.1 based releases.

Affected 12.2-Based Releases

First Fixed Release

Recommended Release

There are no affected 12.2 based releases.

Affected 12.3-Based Releases

First Fixed Release

Recommended Release

There are no affected 12.3 based releases.

Affected 12.4-Based Releases

First Fixed Release

Recommended Release

12.4

Not Vulnerable

 

12.4GC

Not Vulnerable

 

12.4JA

Not Vulnerable

 

12.4JDA

Not Vulnerable

 

12.4JDC

Not Vulnerable

 

12.4JDD

Not Vulnerable

 

12.4JK

Not Vulnerable

 

12.4JL

Not Vulnerable

 

12.4JMA

Not Vulnerable

 

12.4JMB

Not Vulnerable

 

12.4JX

Not Vulnerable

 

12.4MD

Not Vulnerable

 

12.4MDA

Not Vulnerable

 

12.4MR

Not Vulnerable

 

12.4SW

Not Vulnerable

 

12.4T

Not Vulnerable

 

12.4XA

Not Vulnerable

 

12.4XB

Not Vulnerable

 

12.4XC

Not Vulnerable

 

12.4XD

Not Vulnerable

 

12.4XE

Not Vulnerable

 

12.4XF

Not Vulnerable

 

12.4XG

Not Vulnerable

 

12.4XJ

Not Vulnerable

 

12.4XK

Not Vulnerable

 

12.4XL

Not Vulnerable

 

12.4XM

Not Vulnerable

 

12.4XN

Not Vulnerable

 

12.4XP

Not Vulnerable

 

12.4XQ

Not Vulnerable

 

12.4XR

Not Vulnerable

 

12.4XT

Not Vulnerable

 

12.4XV

Not Vulnerable

 

12.4XW

12.4(11)XW8

12.4(20)T4

12.4(22)T3

12.4(24)T2; Available on 23-OCT-2009

12.4XY

12.4(15)XY4

12.4(20)T4

12.4(22)T3

12.4(24)T2; Available on 23-OCT-2009

12.4XZ

12.4(15)XZ1

12.4(20)T4

12.4(22)T3

12.4(24)T2; Available on 23-OCT-2009

12.4YA

12.4(20)YA1

12.4(20)T4

12.4(22)T3

12.4(24)T2; Available on 23-OCT-2009

12.4YB

Not Vulnerable

 

12.4YD

Not Vulnerable

 

12.4YE

Not Vulnerable

 


Workarounds

There are no workarounds to mitigate this vulnerability, other than disabling Extension Mobility. However, auto-registration can be disabled to make exploitation more difficult. Auto-registration can be disabled by the following command:

telephony-service 
  no auto-reg-ephone 

Before disabling auto-registration, all phone MAC addresses need to be explicitly defined on the Cisco Unified CME. Otherwise phones will not be able to register. More information on auto-registration can be found at the following link:

http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/command/reference/cme_a1ht.html#wp1031242

Additional mitigations that can be deployed on Cisco devices in the network are available in the Cisco Applied Mitigation Bulletin companion document for this advisory, which is available at the following link: http://tools.cisco.com/security/center/content/CiscoAppliedMitigationBulletin/cisco-amb-20090923-cme

Obtaining Fixed Software

Cisco has released free software updates that address this vulnerability. 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/docs/general/warranty/English/EU1KEN_.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@cisco.com or security-alert@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@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/en/US/support/tsd_cisco_worldwide_contacts.html 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.

This vulnerability was found internally.

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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20090923-cme

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-bulletins@lists.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

2009-September-23

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/web/about/security/psirt/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.


Download this document (PDF)
View Printable Version