A Reflected Cross-Site Scripting (XSS) vulnerability has been discovered in FAST LTA Silent Brick WebUI, allowing attackers to inject malicious JavaScript code into web pages viewed by users. This issue arises when user-supplied input is improperly handled and reflected directly in the output of a web page without proper sanitization or encoding. Exploiting this vulnerability, an attacker can execute arbitrary JavaScript in the context of the victim's browser, potentially leading to session hijacking, data theft, and other malicious actions. Affected WebUI parameters are "h", "hd", "p", "pi", "s", "t", "x", "y".