The Thrive Optimize WordPress plugin before 1.4.13.3, Thrive Comments WordPress plugin before 1.4.15.3, Thrive Headline Optimizer WordPress plugin before 1.3.7.3, Thrive Leads WordPress plugin before 2.3.9.4, Thrive Ultimatum WordPress plugin before 2.3.9.4, Thrive Quiz Builder WordPress plugin before 2.3.9.4, Thrive Apprentice WordPress plugin before 2.3.9.4, Thrive Visual Editor WordPress plugin before 2.6.7.4, Thrive Dashboard WordPress plugin before 2.3.9.3, Thrive Ovation WordPress plugin before 2.4.5, Thrive Clever Widgets WordPress plugin before 1.57.1 and Rise by Thrive Themes WordPress theme before 2.0.0, Ignition by Thrive Themes WordPress theme before 2.0.0, Luxe by Thrive Themes WordPress theme before 2.0.0, FocusBlog by Thrive Themes WordPress theme before 2.0.0, Minus by Thrive Themes WordPress theme before 2.0.0, Squared by Thrive Themes WordPress theme before 2.0.0, Voice WordPress theme before 2.0.0, Performag by Thrive Themes WordPress theme before 2.0.0, Pressive by Thrive Themes WordPress theme before 2.0.0, Storied by Thrive Themes WordPress theme before 2.0.0, Thrive Themes Builder WordPress theme before 2.2.4 register a REST API endpoint associated with Zapier functionality. While this endpoint was intended to require an API key in order to access, it was possible to access it by supplying an empty api_key parameter in vulnerable versions if Zapier was not enabled. Attackers could use this endpoint to add arbitrary data to a predefined option in the wp_options table.