Hello Plus < 1.7.8 - Authenticated (Contributor+) Missing Authorization to Template Activation via hello_plus_set_as_entire_site

Description

The Hello Plus plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 1.7.7. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with Contributor-level access and above, to publish their own Hello+ header/footer templates and draft currently active templates owned by higher-privileged users.