Short URL < 1.6.5 - Admin+ Cross Site Scripting

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

In the plugin settings, add the POC to the “External URL” or “Comments” fields and reload to see XSS. Note: This must be tested on WordPress v5.8.7