WPFront Notification Bar < 3.5.2 - Reflected Cross-Site Scripting via REQUEST_URI

Description

The WPFront Notification Bar plugin for WordPress is vulnerable to Reflected Cross-Site Scripting in versions up to, and including, 3.5.1. This is due to the debug-log output path (write_debug_logs) reflecting the raw value of $_SERVER['REQUEST_URI'] through vprintf() directly inside a <script> block emitted on wp_footer, without any sanitization or escaping (see the 'Current URL is "%s"' log entry produced by the URL-text display filter in the filter() method). This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a specially crafted link.