Vulnhub-XXE靶机学习

------------恢复内容开始------------

前两天在微信公众号上看见了这个XXE靶场，就想试一试，虽然网上关于这个的文章已经写了太多太多了，但还是要写出来划划水，233333333，摸鱼真快乐.jpg

0x01 安装

这个没什么好说的，解压后vmware导入开机就好了

0x02 信息收集&分析

nmap先直接扫一下，不难确定靶机IP

反正都是靶机，直接-A扫

访问IP是apache2的默认页面，没什么用

但根据nmap的扫描结果，存在robots.txt文件,Disable了XXE路径和admin.php

然而admin.php无法访问，应该是没有权限emmmmm

访问xxe路径得到

随便登陆测试了一下，发现会把用户名输出

Login按钮对应了一个js onclick事件

找到对应的js代码，POST方式发送了xml请求，靶机也叫xxe，直接抓包xxe

<script type="text/javascript">
function XMLFunction(){
    var xml = '' +
        '<?xml version="1.0" encoding="UTF-8"?>' +
        '<root>' +
        '<name>' + $('#name').val() + '</name>' +
        '<password>' + $('#password').val() + '</password>' +
        '</root>';
    var xmlhttp = new XMLHttpRequest();
    xmlhttp.onreadystatechange = function () {
        if(xmlhttp.readyState == 4){
            console.log(xmlhttp.readyState);
            console.log(xmlhttp.responseText);
            document.getElementById('errorMessage').innerHTML = xmlhttp.responseText;
        }
    }
    xmlhttp.open("POST","xxe.php",true);
    xmlhttp.send(xml);
};
</script>

0x03 实现过程

既然已经知道了是xxe，还是linux，肯定直接读etc文件目录下的passwd文件进行测试了，验证成功，xxe漏洞存在，这里还得到了一个r00t，手动混淆肯定有大用(然而后面回来并没有用上)，先记录下来再说

既然文件包含成功了，就尝试包含前面无法访问的admin.php试试

payload php://filter/read=convert.base64-encode/resource=admin.php

得到的结果，Base64 Decode

<?php
   session_start();
?>

<html lang = "en">

   <head>
      <title>admin</title>
      <link href = "css/bootstrap.min.css" rel = "stylesheet">

      <style>
         body {
            padding-top: 40px;
            padding-bottom: 40px;
            background-color: #ADABAB;
         }

         .form-signin {
            max-width: 330px;
            padding: 15px;
            margin: 0 auto;
            color: #017572;
         }

         .form-signin .form-signin-heading,
         .form-signin .checkbox {
            margin-bottom: 10px;
         }

         .form-signin .checkbox {
            font-weight: normal;
         }

         .form-signin .form-control {
            position: relative;
            height: auto;
            -webkit-box-sizing: border-box;
            -moz-box-sizing: border-box;
            box-sizing: border-box;
            padding: 10px;
            font-size: 16px;
         }

         .form-signin .form-control:focus {
            z-index: 2;
         }

         .form-signin input[type="email"] {
            margin-bottom: -1px;
            border-bottom-right-radius: 0;
            border-bottom-left-radius: 0;
            border-color:#017572;
         }

         .form-signin input[type="password"] {
            margin-bottom: 10px;
            border-top-left-radius: 0;
            border-top-right-radius: 0;
            border-color:#017572;
         }

         h2{
            text-align: center;
            color: #017572;
         }
      </style>

   </head>

   <body>

      <h2>Enter Username and Password</h2> 
      <div class = "container form-signin">

         <?php
            $msg = '';
            if (isset($_POST['login']) && !empty($_POST['username']) 
               && !empty($_POST['password'])) {

               if ($_POST['username'] == 'administhebest' && 
                  md5($_POST['password']) == 'e6e061838856bf47e1de730719fb2609') {
                  $_SESSION['valid'] = true;
                  $_SESSION['timeout'] = time();
                  $_SESSION['username'] = 'administhebest';

                echo "You have entered valid use name and password <br />";
        $flag = "Here is the <a style='color:FF0000;' href='/flagmeout.php'>Flag</a>";
        echo $flag;
               }else {
                  $msg = 'Maybe Later';
               }
            }
         ?>
      </div> <!-- W00t/W00t -->

      <div class = "container">

         <form class = "form-signin" role = "form" 
            action = "<?php echo htmlspecialchars($_SERVER['PHP_SELF']); 
            ?>" method = "post">
            <h4 class = "form-signin-heading"><?php echo $msg; ?></h4>
            <input type = "text" class = "form-control" 
               name = "username" 
               required autofocus></br>
            <input type = "password" class = "form-control"
               name = "password" required>
            <button class = "btn btn-lg btn-primary btn-block" type = "submit" 
               name = "login">Login</button>
         </form>

         Click here to clean <a href = "adminlog.php" tite = "Logout">Session.

      </div> 

   </body>
</html>

发现用户名 administhebest

密码MD5解密后为 admin@123

尝试登陆，然而并没有什么用emmmmm

在admin.php里面还看到了一个flagmeout.php文件，使用上面的方式包含

Base64 Decode后

<?php
$flag = "<!-- the flag in (JQZFMMCZPE4HKWTNPBUFU6JVO5QUQQJ5) -->";
echo $flag;
?>

好吧，再来一次这次是Base32了emmmm

L2V0Yy8uZmxhZy5waHA=

套娃233333，Base64

/etc/.flag.php

接下来也没什么好说的了，在文件包含一次，有完整路径了，直接file:///etc/.flag.php

$_[]++;$_[]=$_._;$_____=$_[(++$__[])][(++$__[])+(++$__[])+(++$__[])];$_=$_[$_[+_]];$___=$__=$_[++$__[]];$____=$_=$_[+_];$_++;$_++;$_++;$_=$____.++$___.$___.++$_.$__.++$___;$__=$_;$_=$_____;$_++;$_++;$_++;$_++;$_++;$_++;$_++;$_++;$_++;$_++;$___=+_;$___.=$__;$___=++$_^$___[+_];$À=+_;$Á=$Â=$Ã=$Ä=$Æ=$È=$É=$Ê=$Ë=++$Á[];$Â++;$Ã++;$Ã++;$Ä++;$Ä++;$Ä++;$Æ++;$Æ++;$Æ++;$Æ++;$È++;$È++;$È++;$È++;$È++;$É++;$É++;$É++;$É++;$É++;$É++;$Ê++;$Ê++;$Ê++;$Ê++;$Ê++;$Ê++;$Ê++;$Ë++;$Ë++;$Ë++;$Ë++;$Ë++;$Ë++;$Ë++;$__('$_="'.$___.$Á.$Â.$Ã.$___.$Á.$À.$Á.$___.$Á.$À.$È.$___.$Á.$À.$Ã.$___.$Á.$Â.$Ã.$___.$Á.$Â.$À.$___.$Á.$É.$Ã.$___.$Á.$É.$À.$___.$Á.$É.$À.$___.$Á.$Ä.$Æ.$___.$Á.$Ã.$É.$___.$Á.$Æ.$Á.$___.$Á.$È.$Ã.$___.$Á.$Ã.$É.$___.$Á.$È.$Ã.$___.$Á.$Æ.$É.$___.$Á.$Ã.$É.$___.$Á.$Ä.$Æ.$___.$Á.$Ä.$Á.$___.$Á.$È.$Ã.$___.$Á.$É.$Á.$___.$Á.$É.$Æ.'"');$__($_);

得到了一串奇怪的东西，看大佬的解答，和是一个变形的php webshell，放在本地跑一下就好了，问题来了，我直接包含文件读出来的东西貌似因为编码的原因所以会出现问题，所以最后还是使用php://filter/read=convert.base64-encode/resource=flagmeout.php

包含出来再Base64Decode,添加上php文件标记

<?php
$_[]++;$_[]=$_._;$_____=$_[(++$__[])][(++$__[])+(++$__[])+(++$__[])];$_=$_[$_[+_]];$___=$__=$_[++$__[]];$____=$_=$_[+_];$_++;$_++;$_++;$_=$____.++$___.$___.++$_.$__.++$___;$__=$_;$_=$_____;$_++;$_++;$_++;$_++;$_++;$_++;$_++;$_++;$_++;$_++;$___=+_;$___.=$__;$___=++$_^$___[+_];$脌=+_;$脕=$脗=$脙=$脛=$脝=$脠=$脡=$脢=$脣=++$脕[];$脗++;$脙++;$脙++;$脛++;$脛++;$脛++;$脝++;$脝++;$脝++;$脝++;$脠++;$脠++;$脠++;$脠++;$脠++;$脡++;$脡++;$脡++;$脡++;$脡++;$脡++;$脢++;$脢++;$脢++;$脢++;$脢++;$脢++;$脢++;$脣++;$脣++;$脣++;$脣++;$脣++;$脣++;$脣++;$__('$_="'.$___.$脕.$脗.$脙.$___.$脕.$脌.$脕.$___.$脕.$脌.$脠.$___.$脕.$脌.$脙.$___.$脕.$脗.$脙.$___.$脕.$脗.$脌.$___.$脕.$脡.$脙.$___.$脕.$脡.$脌.$___.$脕.$脡.$脌.$___.$脕.$脛.$脝.$___.$脕.$脙.$脡.$___.$脕.$脝.$脕.$___.$脕.$脠.$脙.$___.$脕.$脙.$脡.$___.$脕.$脠.$脙.$___.$脕.$脝.$脡.$___.$脕.$脙.$脡.$___.$脕.$脛.$脝.$___.$脕.$脛.$脕.$___.$脕.$脠.$脙.$___.$脕.$脡.$脕.$___.$脕.$脡.$脝.'"');$__($_);
?>

最终使用phpstudy，开启错误显示，本地访问这个webshell得到了flag