XSS 全称为 Cross Site Scripting,用户在表单中有意或无意输入一些恶意字符,从而破坏页面的表现!

看看常见的恶意字符XSS 输入:

1.XSS 输入通常包含 JavaScript 脚本,如弹出恶意警告框:<script>alert("XSS");</script>

2.XSS 输入也可能是 HTML 代码段,譬如:

(1).网页不停地刷新 <meta http-equiv="refresh" content="0;">

(2).嵌入其它网站的链接 <iframe src=http://xxxx width=250 height=250></iframe>

    <?PHP
    /**
     * @blog http://www.phpddt.com
     * @param $string
     * @param $low 安全别级低
     */
    function clean_xss(&$string, $low = False)
    {
        if (! is_array ( $string ))
        {
            $string = trim ( $string );
            $string = strip_tags ( $string );
            $string = htmlspecialchars ( $string );
            if ($low)
            {
                return True;
            }
            $string = str_replace ( array ('"', "\\", "'", "/", "..", "../", "./", "//" ), '', $string );
            $no = '/%0[0-8bcef]/';
            $string = preg_replace ( $no, '', $string );
            $no = '/%1[0-9a-f]/';
            $string = preg_replace ( $no, '', $string );
            $no = '/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]+/S';
            $string = preg_replace ( $no, '', $string );
            return True;
        }
        $keys = array_keys ( $string );
        foreach ( $keys as $key )
        {
            clean_xss ( $string [$key] );
        }
    }
    //just a test
    $str = 'phpddt.com<meta http-equiv="refresh" content="0;">';
    clean_xss($str); //如果你把这个注释掉,你就知道xss攻击的厉害了
    echo $str;
    ?>