Upload-labs-04-06

本篇文章仅用于技术交流学习和研究的目的，严禁使用文章中的技术用于非法目的和破坏，否则造成一切后果与发表本文章的作者无关

测试的靶机是作者自己购买的vps搭建的环境，使用了白名单形式访问！

Pass-04

• 根据提示，此关卡直接把所有可能的文件扩展全部过滤了

• 但是百密一疏，此关卡没有过滤.htaccess文件的上传，可以通过上传此文件到目标靶机，且里面写入内容：SetHandler application/x-httpd-php
• 当上述上传成功之后，再随便上传任何后缀名即可，比如上传ant.bmfx  ,或者乱写后缀，只要不是上面过滤的黑名单扩展名即可
• 看如下演示
• 具体关于htaccess的可参考：https://www.zhaosimeng.cn/zqzb/55.html

Pass-05

• 此关卡我怎么尝试都没有成功，我根据网上的资料，通过上传phP,phP3,PHP等绕过方式都没能成功上传，此关卡暂时忽略
• 根据网上资料某博主做的题目并贴出源码发现，当时做此关卡的时候是除去掉如下代码所致：参考博客：https://www.zhaosimeng.cn/writeup/62.html

   $file_ext = strtolower($file_ext); //转换为小写

• 所以实际只要除去上述代码即可绕过，这是本关卡作者考察的目的
• 我通此关卡的源码如下：

$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
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        $file_ext = trim($file_ext); //首尾去空
        
        if (!in_array($file_ext, $deny_ext)) {
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH.'/'.$file_name;
            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！';
    }
}

Pass-06

• 罪了，此关卡查看了源代码，就是互联网上各位博主做的Pass-05 关，该关卡除去掉了过滤大小的代码，所以可以直接使用类似 bmfxshit.phP3 后缀名进行上传即可
• 具体 操作如下：

上述最终上传成功拿下shell