Operating System:

[Win]

Published:

03 December 2019

Protect yourself against future threats.

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             AUSCERT External Security Bulletin Redistribution

                              ESB-2019.4394.2
         Cisco Webex Teams for Windows DLL Hijacking Vulnerability
                              3 December 2019

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

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

Product:           Cisco Webex Teams
                   Cisco Webex Meetings Client
Publisher:         Cisco Systems
Operating System:  Windows
Impact/Access:     Execute Arbitrary Code/Commands -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2019-16001  

Original Bulletin: 
   https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20191120-webex-teams-dll

Revision History:  December  3 2019: Updated advisory to reflect that
                                     Meetings Client is also affected
                   November 21 2019: Initial Release

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

Cisco Webex Teams and Cisco Webex Meetings Client DLL Hijacking Vulnerability

Priority:        Medium
Advisory ID:     cisco-sa-20191120-webex-teams-dll
First Published: 2019 November 20 16:00 GMT
Last Updated:    2019 December 2 16:36 GMT
Version 2.0:     Final
Workarounds:     No workarounds available
Cisco Bug IDs:   CSCvq87642CSCvs05073

CVE-2019-16001   
CWE-427

CVSS Score:
5.3  AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L/E:X/RL:X/RC:X

Summary

  o A vulnerability in the loading mechanism of specific dynamic link libraries
    in Cisco Webex Teams for Windows and Cisco Webex Meetings Client for
    Windows could allow an authenticated, local attacker to perform a DLL
    hijacking attack. To exploit this vulnerability, the attacker would need to
    have valid credentials on the Windows system.

    The vulnerability is due to insufficient validation of the resources loaded
    by the application at run time. An attacker could exploit this
    vulnerability by crafting a malicious DLL file and placing it in a specific
    location on the targeted system. The malicious DLL file would execute when
    the vulnerable application is launched. A successful exploit could allow
    the attacker to execute arbitrary code on the target machine with the
    privileges of another user account.

    There are no workarounds that address this vulnerability.

    This advisory is available at the following link:
    https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
    cisco-sa-20191120-webex-teams-dll

Affected Products

  o Vulnerable Products

    At the time of publication, this vulnerability affected all Cisco Webex
    Teams for Windows and all Cisco Webex Meetings Client for Windows releases.

    See the Details section in the bug ID(s) at the top of this advisory for
    the most complete and current information.

    Products Confirmed Not Vulnerable

    Only products listed in the Vulnerable Products section of this advisory
    are known to be affected by this vulnerability.

Workarounds

  o There are no workarounds that address this vulnerability.

Fixed Software

  o When considering software upgrades , customers are advised to regularly
    consult the advisories for Cisco products, which are available from the
    Cisco Security Advisories and Alerts page , to determine exposure and a
    complete upgrade solution.

    In all cases, customers should ensure that the devices to be upgraded
    contain sufficient memory and confirm that current hardware and software
    configurations will continue to be supported properly by the new release.
    If the information is not clear, customers are advised to contact the Cisco
    Technical Assistance Center (TAC) or their contracted maintenance
    providers.

    Fixed Releases

    For information about fixed software releases, see the Details section in
    the bug ID(s) at the top of this advisory.

Exploitation and Public Announcements

  o The Cisco Product Security Incident Response Team (PSIRT) is not aware of
    any public announcements or malicious use of the vulnerability that is
    described in this advisory.

Source

  o Cisco would like to thank John Tear for reporting this vulnerability.

Cisco Security Vulnerability Policy

  o To learn about Cisco security vulnerability disclosure policies and
    publications, see the Security Vulnerability Policy . This document also
    contains instructions for obtaining fixed software and receiving security
    vulnerability information from Cisco.

URL

  o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
    cisco-sa-20191120-webex-teams-dll

Revision History

  o +---------+----------------------+------------+--------+------------------+
    | Version |     Description      |  Section   | Status |       Date       |
    +---------+----------------------+------------+--------+------------------+
    |         | Added Cisco Webex    |            |        |                  |
    |         | Meetings Client to   | Summary,   |        |                  |
    | 2.0     | the list of affected | Vulnerable | Final  | 2019-November-28 |
    |         | products and link to | Products   |        |                  |
    |         | the related software |            |        |                  |
    |         | defect.              |            |        |                  |
    +---------+----------------------+------------+--------+------------------+
    | 1.0     | Initial public       | -          | Final  | 2019-November-20 |
    |         | release.             |            |        |                  |
    +---------+----------------------+------------+--------+------------------+

- --------------------------END INCLUDED TEXT--------------------

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