By:俺是农村的
漏洞文件:plus/carbuyaction.php

<?php
require_once (dirname(__FILE__) . "/../include/common.inc.php");
define('_PLUS_TPL_', DEDEROOT.'/templets/plus');
require_once DEDEINC.'/dedetemplate.class.php';
require_once DEDEINC.'/shopcar.class.php';
require_once DEDEINC.'/memberlogin.class.php';

if($cfg_mb_open=='N')
{
        ShowMsg("系统关闭了会员功能,因此你无法访问此页面!","javascript:;");
        exit();
}

$cfg_ml = new MemberLogin();

if(!isset($dopost) || empty($dopost)){   //只要$dopost不为空就行,By:俺是农村的。
        ...
}elseif($dopost == 'return'){
        require_once DEDEINC.'/payment/'.$code.'.php';  //变量$code未初始化,By:俺是农村的。
        $pay = new $code;
        $msg=$pay->respond();
        ShowMsg($msg,"javascript:;",0,3000);
        exit(); 
}
?>