The click5 CRM add-on to Contact Form 7 WordPress plugin through 1.0.4 does not have authorisation and CSRF checks when updating options via a REST endpoint, and does not ensure that the option to be updated belongs to the click5 CRM add-on to Contact Form 7 WordPress plugin through 1.0.4. As a result, unauthenticated attackers could change arbitrary blog options, allowing them to create a new administrator account and take over the site.
https://wpscan.com/vulnerability/1dbb03eb-97ba-4a0f-aeea-6a38a47c95e5/