The Burst Statistics – Privacy-Friendly Analytics for WordPress plugin, version 1.5.3, is vulnerable to Post-Authenticated SQL Injection via multiple JSON parameters in the /wp-json/burst/v1/data/compare endpoint. Affected parameters include 'browser', 'device', 'page_id', 'page_url', 'platform', and 'referrer'. This vulnerability arises due to insufficient escaping of user-supplied parameters and the lack of adequate preparation in SQL queries. As a result, authenticated attackers with editor access or higher can append additional SQL queries into existing ones, potentially leading to unauthorized access to sensitive information from the database.