upload-labs通关手册

最近在练习文件上传，所以记录一下自己练习的过程，既能帮助自己以后复习，同时也能帮到初学者。
主要用到的工具是Burpsuite。首先我们应该明白上传文件的目的是什么，通过上传文件将web后门上传并被成功解析。

Pass-01

首先查看源码

通过源码可以看到，第一关是在本地前段进行验证，使用的是前端JS脚本，所以呢，你让它不起作用不就完了，前端我们是可以修改的，在前端JS函数中加上.php文件，然后上传PHP文件。（具体怎么修改，直接查看源代码，然后修改，然后保存本地，再然后点击访问，然后上传即可）

Pass-02

源码：

这个其实也很简单，我们发现它只判断content-type，那所以只要burpsuite抓包修改content-type的类型就可以成功绕过，然后上传。

上传成功如图：

Pass-03

步骤一样，第一步先查看源码

通过源代码分析，我们能够看出来是黑名单过滤，这里有很多绕过方式，抓包修改后缀为php5、php3、phtml、pht等可解析的文件后缀即可

Pass-04

查看源码：

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists(UPLOAD_PATH)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2","php1",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2","pHp1",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf");
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        $file_ext = trim($file_ext); //收尾去空

        if (!in_array($file_ext, $deny_ext)) {
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$file_ext;
            if (move_uploaded_file($temp_file, $img_path)) {
                $is_upload = true;
            } else {
                $msg = '上传出错！';
            }
        } else {
            $msg = '此文件不允许上传!';
        }
    } else {
        $msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
    }
}

还是黑名单过滤，几乎过滤了所有后缀名，但是没有过滤.htaccess，所有先上传一个后缀名为.htaccess文件，里面写上SetHandler application/x-httpd-php，之后所有的文件都会以PHP文件进行解析，那就正常上传图片，然后访问即可

此处用到知识点：

.htaccess文件 -服务
通过.htaccess文件修改解析规则
条件：必须为apache搭建平台

Pass-05

这一关和上一关几乎一模一样，但是没有进行大小写过滤，所以，大小写修改后缀名，然后成功上传。

上传结果如图：

Pass-06

源码：

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists(UPLOAD_PATH)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
        $file_name = $_FILES['upload_file']['name'];
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        
        if (!in_array($file_ext, $deny_ext)) {
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$file_ext;
            if (move_uploaded_file($temp_file,$img_path)) {
                $is_upload = true;
            } else {
                $msg = '上传出错！';
            }
        } else {
            $msg = '此文件不允许上传';
        }
    } else {
        $msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
    }
}

仍然是过滤了很多后缀名，这个时候我们可以在后面加后缀名后面加空格进行绕过

结果如图所示：

成功上传！

Pass-07

源码：

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists(UPLOAD_PATH)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
        $file_name = trim($_FILES['upload_file']['name']);
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        $file_ext = trim($file_ext); //首尾去空
        
        if (!in_array($file_ext, $deny_ext)) {
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH.'/'.$file_name;
            if (move_uploaded_file($temp_file, $img_path)) {
                $is_upload = true;
            } else {
                $msg = '上传出错！';
            }
        } else {
            $msg = '此文件类型不允许上传！';
        }
    } else {
        $msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
    }
}

第7关我们发现多了一个函数，就是首位去空，发现加空格以不再有效。那就没有别的了吗？
当然不是了，出了空格还有很多可以加，它虽然过滤了空格，但是没有过滤“.”！所以，我们可以在后缀名后面加“.”即可绕过上传，正所谓，条条大路通罗马，这里我们也可以看出来，黑名单的弊端！


成功

Pass-08

源码

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists(UPLOAD_PATH)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = trim($file_ext); //首尾去空
        
        if (!in_array($file_ext, $deny_ext)) {
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$file_ext;
            if (move_uploaded_file($temp_file, $img_path)) {
                $is_upload = true;
            } else {
                $msg = '上传出错！';
            }
        } else {
            $msg = '此文件类型不允许上传！';
        }
    } else {
        $msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
    }
}

这里我们发现，大小写不行，加点不行，加空格也不行，但是没有对::$DATA进行过滤,所以在后缀名中加::$DATA进行绕过
知识点：
文件名+::$DATA-服务必须是windows,必须是php,php在window的时候如果文件名+"::$DATA"会把::$DATA之后的数据当成文件流处理,不会检测后缀名.且保持"::$DATA"之前的文件名
他的目的就是不检查后缀名…


成功

Pass-09

源码：

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists(UPLOAD_PATH)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        $file_ext = trim($file_ext); //首尾去空
        
        if (!in_array($file_ext, $deny_ext)) {
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH.'/'.$file_name;
            if (move_uploaded_file($temp_file, $img_path)) {
                $is_upload = true;
            } else {
                $msg = '上传出错！';
            }
        } else {
            $msg = '此文件类型不允许上传！';
        }
    } else {
        $msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
    }
}

这里，在后缀后加上 点+空格+点 即可成功绕过，

pass-10

这里的步骤和之前的一样，重复的我就不再写了，浪费时间，还是先看源码，这是第一步，通过源码去分析它是黑名单过滤还是白名单，然后看它漏掉了哪项。
第10关采用双写绕过，后缀名为 .phphpp 即可成功上传，结果一样，我就不再一一截图了。

Pass-11

查看源码，我们发现11关是白名单判断，因此可以采用%00截断绕过

但是有环境限制： php版本要小于5.3.4，5.3.4及以上

magic_quotes_gpc需要为OFF状态

如果你在做实验时发现一直上传错误，请看你是否满足我上面说的两个环境限制，如果不满足就会上传错误，如果已经设置好，则可以正常上传，得到正确结果。

Pass-12

这一关和11关一样，只是这个是POST提交，上面那个是GET提交，用的方法是一样的！
这里就不再过多阐述

Pass-13

源码：

function getReailFileType($filename){
    $file = fopen($filename, "rb");
    $bin = fread($file, 2); //只读2字节
    fclose($file);
    $strInfo = @unpack("C2chars", $bin);    
    $typeCode = intval($strInfo['chars1'].$strInfo['chars2']);    
    $fileType = '';    
    switch($typeCode){      
        case 255216:            
            $fileType = 'jpg';
            break;
        case 13780:            
            $fileType = 'png';
            break;        
        case 7173:            
            $fileType = 'gif';
            break;
        default:            
            $fileType = 'unknown';
        }    
        return $fileType;
}

$is_upload = false;
$msg = null;
if(isset($_POST['submit'])){
    $temp_file = $_FILES['upload_file']['tmp_name'];
    $file_type = getReailFileType($temp_file);

    if($file_type == 'unknown'){
        $msg = "文件未知，上传失败！";
    }else{
        $img_path = UPLOAD_PATH."/".rand(10, 99).date("YmdHis").".".$file_type;
        if(move_uploaded_file($temp_file,$img_path)){
            $is_upload = true;
        } else {
            $msg = "上传出错！";
        }
    }
}

13关往后与之前不一样，13关之后的是上传图片马。
这里我们看到，它只判断前两个字节，所以自己搞一个图片，然后编辑，将一句话木马写进去，然后上传即可，访问即可得到。

图片上面是乱码，但下面就是被php解析的函数。

Pass-14

跟13关一样。
getimagesize判断图片内置函数可以参考官方文档http://php.net/manual/zh/function.getimagesize.php

Pass-15

这关需要开启php_exif模块，通过php_exif来判断函数类型，具体可以看官方文档http://php.net/manual/zh/function.exif-imagetype.php，接下来还是上传图片马

Pass-16

源码我就不贴了，占地，自己在自己的靶场可以看到。
本关综合判断了后缀名、content-type，以及利用imagecreatefromgif判断是否为gif图片，最后对图片再做了一次二次渲染重新创建，所以在上传图片马的时候将上传后的图片马下载下来进行查看，看看它经过而渲染后的图片中的那些数据没有改变，可以通过16进制编辑器查看，然后我们在这些没有变的地方插入一句话，这样就可以成功上传了。之后的操作与之前的关卡一样

Pass-17

本关考察的是条件竞争
通过白名单检测后缀名，符合就rename改名，不符合就unlink删除文件
可以用burp来发包不断访问，先写一个php写入文件的1.php然后在不断访问这文件就可以看到我们上传的东西了，而且在访问这文件就可以生成另外一个shell了（通过马生成的）

Pass-18

//index.php
$is_upload = false;
$msg = null;
if (isset($_POST['submit']))
{
    require_once("./myupload.php");
    $imgFileName =time();
    $u = new MyUpload($_FILES['upload_file']['name'], $_FILES['upload_file']['tmp_name'], $_FILES['upload_file']['size'],$imgFileName);
    $status_code = $u->upload(UPLOAD_PATH);
    switch ($status_code) {
        case 1:
            $is_upload = true;
            $img_path = $u->cls_upload_dir . $u->cls_file_rename_to;
            break;
        case 2:
            $msg = '文件已经被上传，但没有重命名。';
            break; 
        case -1:
            $msg = '这个文件不能上传到服务器的临时文件存储目录。';
            break; 
        case -2:
            $msg = '上传失败，上传目录不可写。';
            break; 
        case -3:
            $msg = '上传失败，无法上传该类型文件。';
            break; 
        case -4:
            $msg = '上传失败，上传的文件过大。';
            break; 
        case -5:
            $msg = '上传失败，服务器已经存在相同名称文件。';
            break; 
        case -6:
            $msg = '文件无法上传，文件不能复制到目标目录。';
            break;      
        default:
            $msg = '未知错误！';
            break;
    }
}

//myupload.php
class MyUpload{
......
......
...... 
  var $cls_arr_ext_accepted = array(
      ".doc", ".xls", ".txt", ".pdf", ".gif", ".jpg", ".zip", ".rar", ".7z",".ppt",
      ".html", ".xml", ".tiff", ".jpeg", ".png" );

......
......
......  
  /** upload()
   **
   ** Method to upload the file.
   ** This is the only method to call outside the class.
   ** @para String name of directory we upload to
   ** @returns void
  **/
  function upload( $dir ){
    
    $ret = $this->isUploadedFile();
    
    if( $ret != 1 ){
      return $this->resultUpload( $ret );
    }

    $ret = $this->setDir( $dir );
    if( $ret != 1 ){
      return $this->resultUpload( $ret );
    }

    $ret = $this->checkExtension();
    if( $ret != 1 ){
      return $this->resultUpload( $ret );
    }

    $ret = $this->checkSize();
    if( $ret != 1 ){
      return $this->resultUpload( $ret );    
    }
    
    // if flag to check if the file exists is set to 1
    
    if( $this->cls_file_exists == 1 ){
      
      $ret = $this->checkFileExists();
      if( $ret != 1 ){
        return $this->resultUpload( $ret );    
      }
    }

    // if we are here, we are ready to move the file to destination

    $ret = $this->move();
    if( $ret != 1 ){
      return $this->resultUpload( $ret );    
    }

    // check if we need to rename the file

    if( $this->cls_rename_file == 1 ){
      $ret = $this->renameFile();
      if( $ret != 1 ){
        return $this->resultUpload( $ret );    
      }
    }
    
    // if we are here, everything worked as planned :)

    return $this->resultUpload( "SUCCESS" );
  
  }
......
......
...... 
};

和上一关几乎一模一样

Pass-19

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists(UPLOAD_PATH)) {
        $deny_ext = array("php","php5","php4","php3","php2","html","htm","phtml","pht","jsp","jspa","jspx","jsw","jsv","jspf","jtml","asp","aspx","asa","asax","ascx","ashx","asmx","cer","swf","htaccess");

        $file_name = $_POST['save_name'];
        $file_ext = pathinfo($file_name,PATHINFO_EXTENSION);

        if(!in_array($file_ext,$deny_ext)) {
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH . '/' .$file_name;
            if (move_uploaded_file($temp_file, $img_path)) { 
                $is_upload = true;
            }else{
                $msg = '上传出错！';
            }
        }else{
            $msg = '禁止保存为该类型文件！';
        }

    } else {
        $msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
    }
}

本关考察CVE-2015-2348 move_uploaded_file() 00截断，上传webshell，同时自定义保存名称，直接保存为php是不行的,查看源码发现move_uploaded_file()函数中的img_path是由post参数save_name控制的，因此可以在save_name利用00截断绕过

Pass-20

$is_upload = false;
$msg = null;
if(!empty($_FILES['upload_file'])){
    //检查MIME
    $allow_type = array('image/jpeg','image/png','image/gif');
    if(!in_array($_FILES['upload_file']['type'],$allow_type)){
        $msg = "禁止上传该类型文件!";
    }else{
        //检查文件名
        $file = empty($_POST['save_name']) ? $_FILES['upload_file']['name'] : $_POST['save_name'];
        if (!is_array($file)) {
            $file = explode('.', strtolower($file));
        }

        $ext = end($file);
        $allow_suffix = array('jpg','png','gif');
        if (!in_array($ext, $allow_suffix)) {
            $msg = "禁止上传该后缀文件!";
        }else{
            $file_name = reset($file) . '.' . $file[count($file) - 1];
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH . '/' .$file_name;
            if (move_uploaded_file($temp_file, $img_path)) {
                $msg = "文件上传成功！";
                $is_upload = true;
            } else {
                $msg = "文件上传失败！";
            }
        }
    }
}else{
    $msg = "请选择要上传的文件！";
}

通过查看源码可以发现：

$fil{e}_{n}ame经过reset($file) . ‘.’ . $file[count($file) - 1];处理。

如果上传的是数组的话，会跳过$file=explode{(}^{\prime }{.}^{\prime },strtolower($file));。

并且后缀有白名单过滤：

$ext=end($file);
$allow_suffix = array(‘jpg’,‘png’,‘gif’);

而最终的文件名后缀取的是$file[count($file) - 1]，因此我们可以让$file为数组。

$file[0]为smi1e.php/，也就是reset($file)，然后再令$file[2]为白名单中的jpg。

此时end($file)等于jpg，$file[count($file) - 1]为空。

而 $fil{e}_{n}ame=reset($file) . ‘.’ . $file[count($file) - 1];，也就是smi1e.php/.，最终move_uploaded_file会忽略掉/.，最终上传smi1e.php。

总结：

以上就是自己的一些笔记和经验，但是，试想一下，如果没有源代码，你又能通过几关呢？