A vulnerability in the ability for guest users to join meetings via a hyperlink with Cisco Meeting Server could allow an authenticated, remote attacker to enter a meeting with a hyperlink URL, even though access should be denied. The vulnerability is due to the incorrect implementation of the configuration setting Guest access via hyperlinks, which should allow the administrative user to prevent guest users from using hyperlinks to connect to meetings. An attacker could exploit this vulnerability by using a crafted hyperlink to connect to a meeting. An exploit could allow the attacker to connect directly to the meeting with a hyperlink, even though access should be denied. The attacker would still require a valid hyperlink and encoded secret identifier to be connected. Cisco Bug IDs: CSCve20873.