CVE 2021-1420

A vulnerability in certain web pages of Cisco Webex Meetings could allow an unauthenticated, remote attacker to modify a web page in the context of a user's browser. The vulnerability is due to improper checks on parameter values in 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 websites, or the attacker could use this vulnerability to conduct further client-side attacks.

See the CVE page on Mitre.org for more details.