A vulnerability in the web-based management interface of the Cisco Registered Envelope Service could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the web-based management interface of the affected service. The vulnerability is due to insufficient validation of user-supplied input that is processed by the web-based management interface of the affected service. An attacker could exploit this vulnerability by persuading a user of the interface to click a malicious link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the interface or access sensitive browser-based information. Cisco Bug IDs: CVE-2018-0367.