        foreach($course_RET as $period_day)
        {
            $period_days_append_sql .="(sp.start_time<='$period_day[END_TIME]' AND '$period_day[START_TIME]'<=sp.end_time AND DAYS LIKE '%$period_day[DAYS]%') OR ";
        }
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.