A vulnerability in certain web pages of Cisco Webex Meetings and Cisco Webex Meetings Server could allow an unauthenticated, remote attacker to modify a web page in the context of a browser. The vulnerability is due to improper checks on parameter values within affected pages. An attacker could exploit this vulnerability by persuading a user to follow a crafted link that is designed to pass HTML code into an affected parameter. A successful exploit could allow the attacker to alter the contents of a web page to redirect the user to potentially malicious web sites, or the attacker could leverage this vulnerability to conduct further client-side attacks.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webex-html-BJ4Y9tX