NotificationX WordPress Plugin < 2.3.12 Unauthenticated SQL Injection via notification REST endpoint

NotificationX plugin for WordPress 2.0.0 before 2.3.12 contains an unauthenticated SQL injection vulnerability that allows remote attackers to manipulate database queries by supplying an array-form 'id' parameter to /wp-json/notificationx/v1/notification/{id}. Attackers can pass id[1] with crafted SQL, such as time-based SLEEP payloads, along with an api_key derived from md5(home_url()), which flows unsanitized into Database::get_where_query to extract database contents. Exploitation evidence was first observed by the Shadowserver Foundation on 2023-10-18.