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             AUSCERT External Security Bulletin Redistribution

                          ESB-2008.0482 -- [Win]
   Multimedia PC Client - Potential Vulnerability Due to Buffer Overflow
                                9 May 2008

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

Product:              Multimedia PC Client
Publisher:            Nortel
Operating System:     Windows
Impact:               Denial of Service
Access:               Remote/Unauthenticated
CVE Names:            CVE-2008-2080

Original Bulletin:  
  http://support.nortel.com/go/main.jsp?cscat=BLTNDETAIL&id=719698

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Multimedia PC Client - Potential Vulnerability Due to Buffer Overflow

BULLETIN ID: 2008008799, Rev 1 
PUBLISHED: 2008-04-30 
STATUS: Active
REGION: All 
PRIORITY: Critical 
TYPE: Security Advisory

Source:

Nortel would like to acknowledge Parvez Anwar for bringing this
matter to Nortel's attention. Nortel welcomes and encourages
independent researchers to report any potential vulnerabilities via
Email <mailto:NNSATF@nortel.com> and will work with these parties
to assist in data validation to ensure responsible disclosure and
attribution.

Overview:

Nortel has been made aware of a potential vulnerability that may
cause the Multimedia PC Client to experience a Buffer Overflow -
Flooding the Multimedia PC Client with extraneous messaging can
result in the PC Client terminating with an error message. This may
also occur when scanning the Multimedia PC Client with the Nessus
(www.nessus.org) tool using the "Denial of Service" plug-in, and
it is called "Generic flood".

Before taking any action please ensure that you are viewing the
latest official version of this security advisory by referencing
http://www.nortel.com/securityadvisories

For more information: Please contact your next level of support or
visit http://www.nortel.com/contact for support numbers within your
region.  Nortel security advisories: http://nortel.com/securityadvisories
Nortel Partner Information Center (PIC) website:
http://www.nortelnetworks.com/pic

Symptoms:

When the MultiMedia PC Client is flooded with extraneous messages
it can result in the application aborting.

Prevention:

This potential vulnerability can be prevented by upgrading to the
latest software as described in the Resolution section.

Mitigation:

There are no mitigation steps to address this vulnerability, as it
is resolved with a software update. See the Resolution section.

Risk:

This attack can cause a DoS type situation on the Multimedia PC
client and has been brought to Nortel's attention by Parvez Anwar.
To our knowledge, this attack has not been launched against any of
our customers.

Resolution:

To address this vulnerability, Nortel recommends upgrading the
Multimedia PC Client to the latest version. For MCS 5100 Release
3.5 Systems, upgrade to Maintenance Release 3.5.8.3. For MCS 5100
4.0 systems, upgrade to Maintenance Release 4.0.25.3.  Further
information and downloads are available on the Nortel Partner
Information Center (PIC) <http://www.nortel.com/pic>.  To navigate
to the MCS 5100 download page of the PIC use the following steps:

1. Log in to the PIC <http://www.nortel.com/pic> 2. Select "Voice,
Multimedia & Unified Communications" 3. Select "Multimedia Communication
Server 5100" 4. Select "Software Downloads" on the left

Once at the MCS 5100 page of the PIC: - Obtain the 4.0 Maintenance
Release by selecting "MCS 5100 Rls 4.0.25.3 Maintenance Release" -
Obtain the 3.5 Maintenance Release by selecting "MCS 5100 Rls 3.5.8.3
Maintenance Release"

For more information on the MCS 5100, refer to this overview on
nortel.com:
<http://products.nortel.com/go/product_content.jsp?segId=0&catId=null&parId=0&prod_id=52080&locale=en-US>

Attachments:

There are no attachments for this bulletin Products and Releases:
The information in this bulletin is intended to be used with the
following products and associated releases:

PRODUCT RELEASE Multimedia Comm.-MCS5100-MCS5100 3.5 Multimedia
Comm.-MCS5100-MCS5100 4.0 Multimedia Comm.-MCS5100-MCS5100

To view the most recent version of this bulletin, access technical
documentation, search our knowledge base, or to contact a Technical
Support Representative, please visit Nortel Technical Support on
the web at: http://support.nortel.com/. You may also sign up to
receive automatic email alerts when new bulletins are published.

REFERENCE: 
PRE-REQUIRED PATCH: 
PATCH ID:

Copyright 2007 Nortel Networks. All rights reserved. Information
in this document is subject to change without notice. Nortel assumes
no responsibility for any errors that may appear in this document.
The information in this document is proprietary to Nortel Networks.
Nortel recommends any maintenance activities, such as those outlined
in this bulletin, be completed during a local maintenance window.
Nortel, the Nortel logo, and the Globemark design are trademarks
of Nortel Networks. All other trademarks are the property of their
respective owners.


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