Request a Quote <= 2.3.7 - Admin+ Stored Cross-Site Scripting
The plugin does not sanitise and escape some of its settings, allowing high privilege users such as admin to perform cross-Site Scripting attacks even when the unfiltered_html capability is disallowed.
Proof of Concept
Put the following payload in the Misc > No Access Message setting of the plugin: <script>alert(/XSS/);</script>
The XSS will be triggered when accessing a quote without enough privileges