CMSimple Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in CMSimple version 5.2. This issue resides in the Filebrowser External input field, where attackers can inject unfiltered JavaScript. The injected script executes when users interact with the Page or Files tabs, allowing for persistent script injection.

Impact

Exploitation of this vulnerability allows for stored cross-site scripting, where injected scripts are executed in the context of the user.

Reproduction

To reproduce this vulnerability, navigate to the Filebrowser External input field in the CMSimple 5.2 settings. Inject JavaScript code into the input field, which is not filtered before being saved. Once the code is injected, it will execute when the Page or Files tabs are clicked.