upload-labs靶场-Pass-08关-思路以及过程

开始前的小准备

upload-labs靶场 是PHP环境运行的,所以我准备了一个PHP脚本和一张图片
图片好准备,PHP脚本如果不想写的话可以用我的这个获取当前时间的PHP脚本

header("content-type:text/html;charset=utf-8");

date_default_timezone_set("PRC");//设置时区

echo "当前时间为：";

$today = date("Y-m-d D h:i:s A ");

echo $today;

?>

图片默认不清楚放大看!!!

Pass-08

代码:

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists(UPLOAD_PATH)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess");
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = strtolower($file_ext); //转换为小写
        $file_ext = trim($file_ext); //首尾去空
        
        if (!in_array($file_ext, $deny_ext)) {
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$file_ext;
            if (move_uploaded_file($temp_file, $img_path)) {
                $is_upload = true;
            } else {
                $msg = '上传出错！';
            }
        } else {
            $msg = '此文件类型不允许上传！';
        }
    } else {
        $msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
    }
}

这关之前的方法基本上是用不了的

通关过程:

这关其实是利用 Windows系统一个命名特性,Windows系统如果文件名+"::$DATA"会把::$DATA之后的数据当成文件流处理,不会检测后缀名，且保持::$DATA之前的文件名，他的目的就是不检查后缀名

举个例子:
上传文件名为:测试.php::$DATA到Windows系统会自动去掉末尾的::$DATA变成"测试.php或者xxx.php"

通关完成!