$output = $PAGE->get_renderer('mod_attendance');
-$userid = isset($pageparams->studentid) ? $pageparams->studentid : $USER->id;
+// Only users with proper permissions should be able to see any users individual report.
+$userid = (isset($pageparams->studentid) &&
+ ($att->perm->can_manage() || $att->perm->can_take() || $att->perm->can_change())) ? $pageparams->studentid : $USER->id;
$userdata = new attendance_user_data($att, $userid);
echo $output->header();