An issue was discovered in Manager 13.x before 13.0.2.6 and 15.x before 15.0.6 before FreePBX 14.0.10.3. In the Manager module form (html\admin\modules\manager\views\form.php), an unsanitized managerdisplay variable coming from the URL is reflected in HTML, leading to XSS. It can be requested via GET request to /config.php?type=tool&display=manager.