edit

.gitignore

@@ -2,3 +2,4 @@
 .env
 vendor/
 composer.phar
+.user.ini

app/Controllers/UserController.php

@@ -98,7 +98,7 @@ public function invite($request, $response, $args)
     public function doInvite($request, $response, $args)
     {
         $n = $request->getParam('num');
-        if ($n < 1) {
+        if ($n < 1 || $n > $this->user->invite_num) {
             $res['ret'] = 0;
             return $response->getBody()->write(json_encode($res));
         }