Groundhogg privilege escalation lets attackers take over sites

The Groundhogg — CRM, Newsletters, and Marketing Automation plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 4.8.3 via the `create_support_user()` function. This is due to the function identifying the support account solely by matching against publicly hardcoded constants — `user_login` `'groundhogg'` and email addresses `'[email protected]'` / `'[email protected]'` — where the `in_array()` email-equality check at line 238 is not a security boundary because any user fully controls their own email value. This makes it possible for an attacker with an account whose `user_login` is `'groundhogg'` and whose `user_email` matches one of the hardcoded support constants to have that account silently promoted to administrator — and additionally to super admin on multisite when the triggering administrator holds `manage_network_options` — resulting in full site takeover. Exploitation requires a two-actor flow: the attacker must first obtain or pre-plant an account with the hardcoded credentials (possible when open user registration is enabled or another account-creation path exists), after which a legitimate administrator must invoke the support-access feature via the `submit_ticket` or `process_send_support_access` entry points to trigger the promotion.