GREENmod uses named pipes for communication between plugins, the web portal, and the system service, but the access control lists for these pipes are configured incorrectly. This allows an attacker to communicate with the stream and upload any XML or JSON file, which will be processed by the named pipe with the privileges of the user under whose context the service is running. This allows for Server-Side Request Forgery to any Windows system on which the agent is installed and which provides communication via SMB or WebDav.
This issue was fixed in version 2.8.33.