Microsoft released Security Update MS12-020 to close two recently discovered flaws in Microsoft’s implementation of RDP. One of them Microsoft labels as “critical” because it could allow hackers to obtain LocalSystem control on a Windows box with RDP enabled. Administrators should consider running Internet-connectable services on nondefault ports if possible. The only widespread common common service I haven’t been able to get reliably working is FTP: It uses ports 21 and 22 (in passive mode), in passive mode.”]
Source: https://www.csoonline.com/article/2619720/how-to-defeat-the-new-rdp-exploit-the-easy-way.html