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)
1. Go to "Ultimate Dashboard -> Settings -> General".
2. In the "Custom Howdy Text" field, input the XSS payload: `"><script>alert(1)</script>`
3. Save the settings.
4. Observe the XSS payload being executed in the browser when the page is loaded.