In userman 13.0.76.43 through 15.0.20 in Sangoma FreePBX, XSS exists in the user management screen of the Administrator web site, i.e., the/admin/config.php?display=userman URI. An attacker with sufficient privileges can edit the Display Name of a user and embed malicious XSS code. When another user (such as an admin) visits the main User Management screen, the XSS payload will render and execute in the context of the victim user's account.
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.
An issue was discovered in FreePBX core before 3.0.122.43, 14.0.18.34, and 5.0.1beta4. By crafting a request for adding Asterisk modules, an attacker is able to store JavaScript commands in a module name.