The RSVPMaker plugin for WordPress is vulnerable to unauthenticated SQL Injection due to insufficient escaping and parameterization on user supplied data passed to multiple SQL queries in the ~/rsvpmaker-email.php file. This makes it possible for unauthenticated attackers to steal sensitive information from the database in versions up to, and including, 9.3.2. Please note that this is separate from CVE-2022-1453 & CVE-2022-1505.
https://www.wordfence.com/vulnerability-advisories/#CVE-2022-1768
https://gist.github.com/Xib3rR4dAr/441d6bb4a5b8ad4b25074a49210a02cc
http://packetstormsecurity.com/files/176549/WordPress-RSVPMaker-9.3.2-SQL-Injection.html