Guest

Products & Services

Buffer-Overflow-Vulnerabilities-in-the-Cisco-WebEx-Player

Advisory ID: cisco-sa-20111026-webex

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20111026-webex

Revision 1.1

Last Updated  2012 July 18 14:22  UTC (GMT)

For Public Release 2011 October 26 16:00  UTC (GMT)


Summary

Multiple buffer overflow vulnerabilities exist in the Cisco WebEx Recording Format (WRF) player. In some cases, exploitation of the vulnerabilities could allow a remote attacker to execute arbitrary code on the system with the privileges of a targeted user.

The Cisco WebEx Players are applications that are used to play back WebEx meeting recordings that have been recorded on a WebEx meeting site or on the computer of an online meeting attendee. The players can be automatically installed when the user accesses a recording file that is hosted on a WebEx meeting site. The players can also be manually installed for offline playback after downloading the application from www.webex.com.

If the WRF player was automatically installed, it will be automatically upgraded to the latest, nonvulnerable version when users access a recording file that is hosted on a WebEx meeting site. If the WRF player was manually installed, users will need to manually install a new version of the player after downloading the latest version from www.webex.com.

Cisco has released free software updates that address these vulnerabilities.


Note: Effective October 18, 2011, Cisco moved the current list of Cisco Security Advisories and Responses published by Cisco PSIRT. The new location is http://tools.cisco.com/security/center/publicationListing. You can also navigate to this page from the Cisco Products and Services menu of the Cisco Security Intelligence Operations (SIO) Portal. Following this transition, new Cisco Security Advisories and Responses will be published to the new location. Although the URL has changed, the content of security documents and the vulnerability policy are not impacted. Cisco will continue to disclose security vulnerabilities in accordance with the published Security Vulnerability Policy.

Affected Products

The vulnerabilities disclosed in this advisory affect the Cisco WRF players. The Microsoft Windows, Apple Mac OS X, and Linux versions of the players are all affected. Review the following table for the list of releases that contain the nonvulnerable code. Affected versions of the players are those prior to client build T26 SP49 EP40 and T27 SP28. These build numbers are available only to WebEx site administrators. End users will see a version such as "Client build: 27.25.4.11889." This indicates the server is running software version T27 SP25 EP4.

To determine whether a Cisco WebEx meeting site is running an affected version of the WebEx client build, users can log in to their Cisco WebEx meeting site and go to the Support > Downloads section. The version of the WebEx client build will be displayed on the right side of the page under "About Support Center." See "Software Versions and Fixes" for details.

Cisco recommends that users upgrade to the most current version of the player that is available from www.webex.com/downloadplayer.html. If the player is no longer needed, it can be removed using the "Mac Cisco-WebEx Uninstaller" or "Meeting Services Removal tool" available at support.webex.com/support/downloads.html.

Users can manually verify the installed version of the WRF player to determine whether it is affected by these vulnerabilities. To do so, an administrator must examine the version numbers of the installed files and determine whether the version of the file contains the fixed code. Detailed instructions on how to verify the version numbers are provided in the following sections. 

The following tables provide the first nonvulnerable version of each object.

Microsoft Windows

Two dynamically linked libraries (DLLs) were updated on the Microsoft Windows platform to address the vulnerabilities that are described in this advisory. These files are in the folder C:\Program Files\WebEx\Record Playback or C:\Program Files (x86)\Webex\Record Player. The version number of a DLL can be obtained by browsing the Record Playback directory in Windows Explorer, right-clicking on the file name, and choosing Properties. The Version or Details tab of the Properties page provides details on the library version. The following table gives the first fixed version number for each DLL. If the installed versions are equal to or greater than the versions provided in the table, the system is not vulnerable. 

Library

T26 SP49 EP40

T27 SP11 EP26

T27 SP21 EP9

T27 SP25 EP3

T27 SP28

atas32.dll

Not vulnerable

2.6.11.0

2.6.21.5

2.6.25.0

2.6.28.0

atdl2006.dll

2.5.49.4000

2.6.1123.1

2.6.21.1

2.6.20.0

Not vulnerable

Mac

A package bundle was updated on the Macintosh platform to address the vulnerabilities that are described in this advisory. This file is in each user's home directory, which can be accessed in ~/Library/Application Support/WebEx Folder/824 for systems connected to servers running T26 and ~/Library/Application Support/WebEx Folder/924 for systems connected to servers running T27. The version can be obtained by browsing to the appropriate folder in Finder and control-clicking the filename. When the menu is displayed, select show package contents and then double-click the Info.plist file. The version number is shown at the bottom of the displayed table.

Bundle

T26 SP49 EP40

T27 SP11 EP26

T27 SP21 EP9

T27 SP25 EP3

T27 SP28

asplayback.bundle

6.0.49.40

6.10.11.25

6.10.21.9

6.0.25.3

5.25.27.28

Linux

A shared object was updated on the Linux platform to address the vulnerabilities that are described in this advisory. This file is in the ~/.webex directory. The version number of the shared object can be obtained by performing a directory listing with the ls command. The version number is provided after the .so extension.

Shared Object

T26 SP49 EP40

T27 SP11 EP26

T27 SP21 EP9

T27 SP25 EP3

T27 SP28

atascli.so

1.0.26.41

1.11.27.15

1.0.27.17

1.25.27.17

1.28.27.17

Vulnerable Products

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

Products Confirmed Not Vulnerable

The Cisco WebEx Player for the WebEx Advanced Recording Format (ARF) file format is not affected by the vulnerabilities described in this document.

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

Details

The WebEx meeting service is a hosted multimedia conferencing solution that is managed and maintained by Cisco WebEx. The WRF file format is used to store WebEx meeting recordings that have been recorded on a WebEx meeting site or on the computer of an online meeting attendee. The players are applications that are used to play back and edit recording files (files with a .wrf extension). The WRF players can be automatically installed when the user accesses a recording file that is hosted on a WebEx meeting site (for stream playback mode). The WRF players can also be manually installed after downloading the application from www.webex.com/downloadplayer.html to play back recording files locally (for offline playback mode).

The Cisco WebEx Recording Format (WRF) Player is affected by the following vulnerabilities:

Cisco WebEx Player WRF Parsing Vulnerability
This vulnerability has been assigned the following Common Vulnerabilities and Exposures (CVE) identifier: CVE-2011-3319

Cisco WebEx Player ATAS32 Processing Vulnerability
This vulnerability has been assigned the following Common Vulnerabilities and Exposures (CVE) identifier: CVE-2011-4004

The vulnerabilities may cause the player application to crash or, in some cases, remote code execution could occur.

To exploit one of these vulnerabilities, the player application would need to open a malicious WRF file. An attacker may be able to accomplish this exploit by providing the malicious recording file directly to users (for example, by using e-mail) or by directing a user to a malicious web page. The vulnerabilities cannot be triggered by users who are attending a WebEx meeting.

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.

Multiple Cisco WebEx Player Buffer Overflow Vulnerabilities

Calculate the environmental score of these Vulnerabilities
CVSS Base Score - 9.3
Access Vector Access Complexity Authentication Confidentiality Impact Integrity Impact Availability Impact
Network Medium None Complete Complete Complete
CVSS Temporal Score - 7.7
Exploitability Remediation Level Report Confidence
Functional Official-Fix Confirmed

Impact

Successful exploitation of the vulnerabilities described in this document could cause the Cisco WRF player application to crash and, in some cases, allow a remote attacker to execute arbitrary code on the system with the privileges of the user who is running the WRF player application.

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.

These vulnerabilities are first fixed in the following versions: 

  • T26 SP49 EP40
  • T27 FR20
  • T27 SP11 EP23
  • T27 SP21 EP9
  • T27 SP23
  • T27 SP25 EP3
  • T27 SP28

The client build is listed in the Support > Downloads section of the WebEx page after a user authenticates. WebEx bug fixes are cumulative in a major release. For example, if release T27 SP22 EP9 is fixed, release T27 SP22 EP23 will also have the software fix.  End users will see a version such as "Client build: 27.25.4.11889." This indicates the server is running software version T27 SP25 EP4.

If a WRF player was automatically installed, it will be automatically upgraded to the latest, nonvulnerable version when users access a recording file that is hosted on a WebEx meeting site.

If a WRF player was manually installed, users will need to manually install a new version of the player after downloading the latest version from www.webex.com/downloadplayer.html. If the player is no longer needed, it can be removed using the "Mac Cisco-WebEx Uninstaller" or "Meeting Services Removal tool" available at support.webex.com/support/downloads.html

Workarounds

There are no workarounds for the vulnerabilities disclosed in this advisory.

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/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

This section does not apply for vulnerabilities in Cisco WebEx products.

Customers using Third Party Support Organizations

This section does not apply for vulnerabilities in Cisco WebEx products.

Customers without Service Contracts

This section does not apply for vulnerabilities in Cisco WebEx products.

Exploitation and Public Announcements

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

These vulnerabilities were reported to Cisco by TippingPoint. Cisco would like to thank TippingPoint for reporting these vulnerabilities to us.

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-20111026-webex

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 1.1 2012-July-18 Updated advisory metatags.
Revision 1.0 2011-October-26 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.