Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2019.3690 Cisco Webex Meetings Enumeration Attack 2 October 2019 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco Webex Meetings Publisher: Cisco Systems Operating System: Windows UNIX variants (UNIX, Linux, OSX) Impact/Access: Access Confidential Data -- Remote/Unauthenticated Resolution: Mitigation Original Bulletin: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20191001-webex-enum - --------------------------BEGIN INCLUDED TEXT-------------------- Cisco Webex Meetings Enumeration Attack Priority: Informational Advisory ID: cisco-sa-20191001-webex-enum First Published: 2019 October 1 13:00 GMT Version 1.0: Final Workarounds: Yes Summary o Cisco Webex Meetings is an enterprise solution for hosting online meetings that offers video conferencing, screen sharing, and webinar capabilities that support hundreds of participants. Cisco Webex Meetings utilizes a nine-digit number as a user-friendly meeting identifier that can be easily typed in to join a meeting from all types of endpoints. On July 24th, 2019, Shreyans Mehta of Cequence Security and the CQ Prime Research Team reported to Cisco that an attacker could take advantage of one of the Webex Meetings API calls to enumerate all the meeting numbers in use by an organization on the platform at a certain moment in time. This advisory is available at the following link: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/ cisco-sa-20191001-webex-enum Affected Products o Vulnerable Products The issue described in this advisory affects Cisco Webex Meetings. Products Confirmed Not Vulnerable Only products listed in the Vulnerable Products section of this advisory are known to be affected by this attack method. Cisco has confirmed that Cisco Webex Meeting Server, used for on-premise deployments, does not exhibit this behavior. Details o As part of the process of creating a meeting, Webex will randomly generate and assign a nine-digit identifier that invitees can later use to join the meeting. Shreyans Mehta of Cequence Security and the CQ Prime Research Team have reported to Cisco that one of the Webex API calls could be used to enumerate all of the meeting numbers for ongoing or future meetings. The response to the invoked API call would allow an attacker to determine: Whether a certain meeting number is in use, and Whether the meeting is password protected The attacker could use the gathered information to try to join meetings that are not password protected. If the attacker was to join the meeting using this information, they would still be listed as a participant and could be expelled by the host. For password-protected meetings, the attacker could recover the meeting number, but would not be able to uncover the meeting title, schedule or host name, or join the meeting. Recommendations o The most effective step to strengthen the security of all meetings is to require a password. Passwords protect against unauthorized attendance because only users with access to the password are able to join. Cisco recommends that administrators maintain their sites with the default configuration that makes using a password mandatory when users are setting up a meeting. This recommendation, with other security best practices, is documented in the guide Cisco WebEx Best Practices for Secure Meetings for Site Administrators and Hosts . Cisco Webex offers a default, randomly generated password as part of the meeting setup process in sites that do not mandate password protection. Customers are able to override this password with a user-defined password or disable password protection if the site allows it. Exploitation and Public Announcements o The Cisco Product Security Incident Response Team (PSIRT) is not aware of any malicious use of the attack method that is described in this advisory. Source o Cisco would like to thank Shreyans Mehta of Cequence Security and the CQ Prime Research Team for reporting this attack method. 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-20191001-webex-enum Revision History o +---------+--------------------------+---------+--------+-----------------+ | Version | Description | Section | Status | Date | +---------+--------------------------+---------+--------+-----------------+ | 1.0 | Initial public release. | - | Final | 2019-October-01 | +---------+--------------------------+---------+--------+-----------------+ - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBXZQDV2aOgq3Tt24GAQjrAQ//fxjLqnf3Onp2ZLJCWm8YpcL0o5Z+fiet x4pLluYUX1gVNSi3qI1KbDv6ABmpX2uQXjZRloJMeMPrv831lewBLct51WuUonTn +lhMROxmAqwnDEi+doFnIS3KadzcQMtqLPrAaa7bqNTQ5Qdivl0WbwDjf47+/em/ xoc2AB8ayysNIkNgPnUKYg5k2heE6xDT6PlWIfmSei/hck3nT8IlP5pTO894C52+ oyNu/9uAF0keaaYExSGA2T0M2wkjZOW6vhMqUZ0JuLsAHax9/TUti7rNq6f+Did5 4jzVDG0ML2nidFYdaF/vnTzmQvFowfBvi2digXV0/4SwnVP/xjDFvJSsYIfrucDE +TKyNDF8DILhTO9bTckLC5cvIxBXstochgsjhA2IRleYKkGqvKHzo7OFGp5Eicu1 arBZw7mVlwaDjKgVsVzhLQsnApLE6CNYc6pbRIaB/sqeu6EobVHg+C79n6BYecQp 4puMkdnRCxm3148ZQzfFGuQZtkxfvkV/+pXDPMgtTbZ1Rbfz91I//CRJ6VfMRpUb /3g8WnCl8rXKjl7u+tp3CdRHKFsAJytJA46ccMpmkvURXEInCMvxibMV4o6lzFj+ +i97riun0488s7SJArmB5z1ayRVsGD/OOyBpiN1wW8A1jdF1+ZDYUBd7LPAxY2zz PbVYvSU05Uc= =660l -----END PGP SIGNATURE-----