The File Sharing & Download Manager – User Private Files plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'fldr_ttl' parameter in all versions up to, and including, 2.1.6 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
https://plugins.trac.wordpress.org/browser/user-private-files/tags/2.1.6/templates/render.php#L68
https://plugins.trac.wordpress.org/browser/user-private-files/tags/2.1.6/templates/files.php#L165
https://plugins.trac.wordpress.org/browser/user-private-files/tags/2.1.6/templates/files.php#L160