Icegram Mailer <= 1.0.12 - Authenticated (Administrator+) SQL Injection via 'fields' Parameter

The Icegram Mailer plugin for WordPress is vulnerable to SQL Injection via the 'fields' parameter in versions up to, and including, 1.0.12. This is due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query in the Icegram_Mailer_Logs_Table::get_logs() function, where each element of the `fields` array received from $_REQUEST['data'] is joined verbatim into the SELECT clause via implode() with no whitelist, escaping, or prepared-statement placeholder. This makes it possible for authenticated attackers, with Administrator-level access and above, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.