        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 uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.