Cross-Site Scripting (XSS) vulnerability in Intermark IT's WebControl CMS v3.5. This vulnerability allows an attacker to execute JavaScript code or inject a dynamic iframe into the victim’s browser by sending a malicious URL via the 'urlDestino' parameter in '/portal.do'. This vulnerability can be exploited to steal sensitive user data, such as session cookies, display phishing interfaces, or perform actions on the user’s behalf.