uploads_labs前9题

upload-labs详解

  • 1.代码使用的函数详解
  • 2.uploads_labs
      • 1.Pass-01
      • 2.Pass-02
      • 3.Pass-03
      • 4.Pass-04
      • 5.Pass-05
      • 6.Pass-06
      • 7.Pass-07
      • 8.Pass-08
      • 9.Pass-09


1.代码使用的函数详解

2.uploads_labs

1.Pass-01

function checkFile() {
    var file = document.getElementsByName('upload_file')[0].value;
    if (file == null || file == "") {
        alert("请选择要上传的文件!");
        return false;
    }
    //定义允许上传的文件类型
    var allow_ext = ".jpg|.png|.gif";
    //提取上传文件的类型
    var ext_name = file.substring(file.lastIndexOf("."));//截取文件后缀
    //判断上传文件类型是否允许上传
    if (allow_ext.indexOf(ext_name + "|") == -1) {
        var errMsg = "该文件不允许上传,请上传" + allow_ext + "类型的文件,当前文件类型为:" + ext_name;
        alert(errMsg);
        return false;
    }
}

如上为Pass-01核心代码,代码解释如上所示,前端只允许我们上传".jpg|.png|.gif"为后缀的文件,我们可以把一句话木马文件先改成".jpg|.png|.gif"为后缀的文件,抓包后再改回来

2.Pass-02

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) { //判断是否提交了
    if (file_exists($UPLOAD_ADDR)) { //判断文件路径是否存在
        if (($_FILES['upload_file']['type'] == 'image/jpeg') || ($_FILES['upload_file']['type'] == 'image/png') || ($_FILES['upload_file']['type'] == 'image/gif')) { //设置了白名单,只有 'image/jpeg'等文件后缀才可以上传,其他文件类型不可以上传
            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 = '文件类型不正确,请重新上传!';
        }
    } else {
        $msg = $UPLOAD_ADDR.'文件夹不存在,请手工创建!';
    }
}

如上为Pass-02核心代码,代码解释如上所示,后端只允许我们上传"image/jpeg "等类型的文件,我们可以上传一句话木马文件,并且抓包后把文件类型改成image/jpeg

  • 上传1.php:
    uploads_labs前9题_第1张图片
  • 更改类型:
    uploads_labs前9题_第2张图片

3.Pass-03

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array('.asp','.aspx','.php','.jsp');  //黑名单,就是不允许上传的文件的后缀
        $file_name = trim($_FILES['upload_file']['name']); //去除$_FILES['upload_file']['name']左右的空格
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');  //如果$file_name是1.php,取php
        $file_ext = strtolower($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 = '不允许上传.asp,.aspx,.php,.jsp后缀文件!';
        }
    } else {
        $msg = $UPLOAD_ADDR . '文件夹不存在,请手工创建!';
    }
}

如上为Pass-03核心代码,代码解释如上所示,没有过滤php5,phtml等后缀,如果平台又可以解析php5,phtml(apacher 开启了AddType application/x-httpd-php .php .phtml),就可以上传后缀为php5,phtml的文件,和php一模一样的(解析的前提是修改httpd.conf,) 现在我的是php的环境,那我们能够用php4、php5,或者说是phtml的方式进行绕过,那当然,如果说我们是asp的环境,那我们可以用asa、cer、cdx,这样的后缀名,进行绕过,那如果说是我们aspx的,这种网站,我们能够用ashx、asmx、ascx、esms,那当我们遇到jsp的时候,我们可以用jspx、jspf,这种后缀名进行绕过

  • 上传phtml文件后缀的文件:
    uploads_labs前9题_第3张图片

4.Pass-04

$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");  //几乎限制了所有脚本文件的上传,没有绕过.htaccess文件,可以先上传.htaccess构造.htaccess解析漏洞
        $file_name = trim($_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!';
    }
}

如上操作请查看.htaccess漏洞和图片马的使用

5.Pass-05

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".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"); //绕过了部分脚本文件,并且下面在进行比对的时候没有进行全部大写,全部小写的代码,及缺少strtolower()
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = deldot($file_name);//删除文件名末尾的点
        $file_ext = strrchr($file_name, '.');
        $file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字符串::$DATA
        $file_ext = trim($file_ext); //首尾去空

        if (!in_array($file_ext, $deny_ext)) {
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $_FILES['upload_file']['name'])) {
                $img_path = $UPLOAD_ADDR . '/' . $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!';
    }
}

所以如上代码,我们可以上传木马文件,文件后缀为Php就可以绕过,由于windows和LInux一样,你大小写后都会自动变成小写,所以我们要在抓包的时候更改文件后缀
uploads_labs前9题_第4张图片

6.Pass-06

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".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 = $_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
        
        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 . '/' . $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!';
    }
}

前两个也没什么不同,但是将所有的后缀都给过滤了,仔细看了看,发现这个题目没有对后缀名末尾做去空处理。也就是说这道题目的考点是空格绕过,所以文件抓包后在php后缀下加上空格再发送就可以了(注意目标服务器需要是apache服务器,nginx服务器则不能够这样)

7.Pass-07

$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".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 = $_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
        
        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 . '/' . $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!';
    }
}

这一题比前面三题来说,将所有改过滤的都过滤了,这下要想想其他的绕过方法了没有对后缀名末尾的点进行处理,利用windows特性,会自动去掉后缀名中最后的”.”,可在后缀名中加”.”绕过,这题的考点是.绕过。

8.Pass-08

 $is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".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, $deny_ext)) {
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $_FILES['upload_file']['name'])) {
                $img_path = $UPLOAD_ADDR . '/' . $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!';
    }
}

看下这个题目,又将文件名末尾的点给删除了,在看看和上一个代码的差别,但是我们可以看到这个代码没有了::$DATA$file_ext = str_ireplace('::$DATA', '', $file_ext);//去除字串::$DATA也就是没了这一句,那我们把这个加到后面不就可以过滤了吗

uploads_labs前9题_第5张图片

9.Pass-09

 $is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array(".php",".php5",".php4",".php3",".php2",".html",".htm",".phtml",".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, $deny_ext)) {
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $_FILES['upload_file']['name'])) {
                $img_path = $UPLOAD_ADDR . '/' . $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!';
    }
}

这次可狠了,前面所有可以利用的都给过滤了,分析下代码,先将首尾去空,又去除了::$DATA又转换为小写,再删去末尾的点。这样一来我们构造文件名,使其经过过滤后得到的还是php的文件名不就行了,所以就1.php. . 就可以绕过,也就是点+空格+点+空格绕过
uploads_labs前9题_第6张图片

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