Paytium < 4.3.7 - Admin+ Stored XSS

The plugin 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).

PoC

1. Go to Playtium » Settings and in the ‘Test’ mode, add the payload to both ‘Live API Key’ and ‘Test API Key’. The payload is: “><” 2. Save the changes and go to Playtium » Setup wizard to see the XSS popup.