The Simple Banner WordPress plugin before 3.0.4 does not sanitise and escape 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).
https://wpscan.com/vulnerability/02b5c1a8-cf2a-4378-bfda-84d841d88a18/