CMS Made Simple 2.2.14 - Persistent Cross-Site Scripting (Authenticated)

# Exploit Title: CMS Made Simple 2.2.14 - Persistent Cross-Site Scripting (Authenticated)
# Google Dork: -
# Date: 2020-09-29
# Exploit Author: Roel van Beurden
# Vendor Homepage: https://www.cmsmadesimple.org/
# Software Link: http://s3.amazonaws.com/cmsms/downloads/14793/cmsms-2.2.14-install.zip
# Version: 2.2.14
# Tested on: Linux Ubuntu 18.04
# CVE: CVE-2020-24860


1. Description:
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CMS Made Simple 2.2.14 allows an authenticated user with access to the Content Manager to edit content and put persistent XSS payload in the affected text fields. The user
can get cookies from every authenticated user who visits the website.


2. Affected parameters:
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Content > Content Manager > Edit some page > Logic (tab) > Page Specific Metadata (text field)
Content > Content Manager > Edit some page > Logic (tab) > Smart data or logic that is specific to this page (text field)


3: Example payload:
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<script>alert(document.cookie);</script>


4: Exploitation demo:
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youtube.com/watch?v=M6D7DmmjLak&t=22s