Upload-labs（Pass7-8）

前言

作者简介：不知名白帽，网络安全学习者。

博客主页：https://blog.csdn.net/m0_63127854?type=blog

Upload-labs专栏：https://blog.csdn.net/m0_63127854/category_11850783.html

网络安全交流社区：https://bbs.csdn.net/forums/angluoanquan

练习网站：upload-labs

注意：

能运行<?php phpinfo();?>

就能运行<?php eval($_POST['cmd'])?>一句话木马

本文使用<?php phpinfo();?>主要是为了简便

知识点

$_FILES[表单提交过来的name]

[name]:获取到的文件名

[type]: 获取到的文件类型(MIMETYPE)

[tmp_name]:文件临时存放的路径

[error]: 上传文件报错信息(为空则上传成功)

[size]:上传文件的大小

Move_uploaded_file(需要移动的文件,要移动到的位置)

Strrchr(指定字符串,匹配的字符) --指针指到指定的字符的位置，取之后的值

Trim() --去除字符串中的前后空格

Rtrim() --去除右空格

Ltrim() --去除左空格

Strtolower() --将字符串转为小写

Str_ireplace --(被转换的字符串，替换成的字符串，需要查找的字符串)

在需要查找的字符串中查找需要被替换的字符串，替换为指定的字符串

Pass-07

代码：

$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",".ini");
        $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)) {
            $temp_file = $_FILES['upload_file']['tmp_name'];
            $img_path = UPLOAD_PATH.'/'.date("YmdHis").rand(1000,9999).$file_ext;
            if (move_uploaded_file($temp_file,$img_path)) {
                $is_upload = true;
            } else {
                $msg = '上传出错！';
            }
        } else {
            $msg = '此文件不允许上传';
        }
    } else {
        $msg = UPLOAD_PATH . '文件夹不存在,请手工创建！';
    }
}

提示：

没有进行首尾去空

缺少代码

$file_ext = trim($file_ext); //首尾去空

我们可以进行空格绕过

解题思路：

上传phpinfo.php进行BP抓包

上传成功后右键打开链接

Pass-08

代码：

$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",".ini");
        $file_name = trim($_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)) {
            $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！';
    }
}

提示：

缺少代码

 $file_name = deldot($file_name)

 没有删除文件名末尾后的点

所以进行点绕过

解题思路：

上传phpinfo.php文件进行BP抓包

上传成功后右键打开链接