Groundhogg <= 4.8.3 - Unauthenticated Privilege Escalation to Support User Identity Confusion

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 'support@groundhogg.io' / 'help@groundhogg.io' — 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.