Advisory ID: cisco-sa-20110201-webex
For Public Release 2011 Februrary 1 16:00 UTC (GMT)
Multiple buffer overflow vulnerabilities exist in the Cisco WebEx
Recording Format (WRF) and Advanced Recording Format (ARF) Players. In some
cases, exploitation of the vulnerabilities could allow a remote attacker to
execute arbitrary code on the system of a targeted user.
The Cisco WebEx Players are applications that are used to
play back WebEx meeting recordings that have been recorded on the computer of
an on-line meeting attendee. The players can be automatically installed when
the user accesses a recording file that is hosted on a WebEx server. The player
can also be manually installed for offline playback after downloading the
application from www.webex.com
If the WebEx recording player was automatically installed,
it will be automatically upgraded to the latest, non-vulnerable version when
users access a recording file that is hosted on a WebEx server. If the WebEx
recording player was manually installed, users will need to manually install a
new version of the player after downloading the latest version from
Cisco has released free software updates that address these
This advisory is posted at
The vulnerabilities disclosed in this advisory affect the Cisco WebEx
recording players. Microsoft Windows, Apple Mac OS X, and Linux versions of the
player are all affected. Affected versions of the players are those prior to
client builds T27LC SP22 and T27LB SP21 EP3.
To determine whether a Cisco WebEx server is running an
affected version of the WebEx client build, users can log in to their Cisco
WebEx server 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
No other Cisco products are currently known to be affected by these
The WebEx meeting service is a hosted multimedia conferencing solution
that is managed and maintained by Cisco WebEx. The WRF and ARF file formats are
used to store WebEx meeting recordings that have been recorded on the computer
of an on-line meeting attendee. The players are applications that are used to
play back and edit recording files (files with .wrf and .arf extensions). The
recording players can be automatically installed when the user accesses a
recording file that is hosted on a WebEx server (for stream playback mode). The
recording players can also be manually installed after downloading the
to play back recording
files locally (for offline playback mode).
Multiple buffer overflow vulnerabilities exist in the WRF
and ARF players. The vulnerabilities may lead to a crash of the player
application 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 or ARF 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 vulnerability cannot be triggered by users who are
attending a WebEx meeting.
These vulnerabilities have been assigned the following
Common Vulnerabilities and Exposures (CVE) identifiers:
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
Cisco has also provided a CVSS calculator to help compute
the environmental impact for individual networks at
Multiple Cisco WebEx Player Buffer Overflow
Calculate the environmental score of
CVSS Base Score - 9.3
CVSS Temporal Score - 7.7
Successful exploitation of the vulnerabilities described in this
document could result in a crash of the Cisco WebEx ARF Player or WRF Player
application 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 recording
When considering software upgrades, also consult
and any subsequent advisories to determine exposure and a complete upgrade
These vulnerabilities are first fixed in T27LC SP22 and
T27LB SP21 EP3. For customers who are running T27LC SP22, the client build will
be represented as 27.22SP.0.9253. The fix for customers who are running T27LB
SP21 will be deployed by WebEx over the next few weeks. The client build will
be determined after the software is deployed.
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 27.22SP.0 is fixed,
release 27.22SP.1 will also have the software fix.
If a recording 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 server.
If a WebEx recording player was manually installed, users
will need to manually install a new version of the player after downloading the
latest version from
There are no workarounds for the vulnerabilities disclosed in this
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
, or as otherwise set forth at Cisco.com Downloads at
Do not contact firstname.lastname@example.org or email@example.com
for software upgrades.
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 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 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)
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
for additional TAC contact information, including localized telephone numbers,
and instructions and e-mail addresses for use in various languages.
The Cisco PSIRT is not aware of any public announcements or malicious
use of the vulnerability described in this advisory.
These vulnerabilities were either found during internal
testing or reported to Cisco by a variety of sources, including Core Security,
TippingPoint, and Fortinet's FortiGuard Labs.
Cisco would like to thank these organizations for reporting
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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.
This advisory is posted on Cisco's worldwide website at :
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.
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.
Initial public release.