A vulnerability in the web-based management interface of Cisco Jabber Guest could allow an unauthenticated remote attacker to conduct a cross-site scripting (XSS) attack against a user of the web-based management interface of an affected device. The vulnerability exists because the web-based management interface of the affected device does not properly validate user-supplied input. An attacker could exploit this vulnerability by persuading a user to click a malicious link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or to access sensitive browser-based information. This vulnerability affects Cisco Jabber Guest releases 11.1(2) and earlier.