Pretty Url <= 1.5.4 - Admin+ Stored XSS in plugin settings

Plugin does not sanitize and escape the URL field in the plugin settings, which could allow high-privilege users to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup).

PoC

1. In the "Enter the URL: field, add the XSS payload ![](x) and save 2. Payload will be executed upon reload.