anuko timetracker is an open source time tracking system. Boolean-based blind SQL injection vulnerability existed in Time Tracker invoices.php in versions prior to 220.127.116.1181. This was happening because of a coding error after validating parameters in POST requests. There was no check for errors before adjusting invoice sorting order. Because of this, it was possible to craft a POST request with malicious SQL for Time Tracker database. This issue has been fixed in version 18.104.22.16881. Users are advised to upgrade. Users unable to upgrade may insert an additional check for errors in a condition before calling `ttGroupHelper::getActiveInvoices()` in invoices.php.