The plugin does not sanitize and escapes some of its settings, which could allow high-privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example, in multisite setup).
Inject an XSS payload in the title by going to Settings Β» WP Attachments Β» Settings Β» List Head. Now, inject XSS payload & HTML injection (