You can scan your machine to detect RDP vulnerability by using this tool.
Checks if a machine is vulnerable to MS12-020 RDP vulnerability.
The Microsoft bulletin MS12-020 patches two vulnerabilities: CVE-2012-0152 which addresses a denial of service vulnerability inside Terminal Server, and CVE-2012-0002 which fixes a vulnerability in Remote Desktop Protocol. Both are part of Remote Desktop Services.
The script works by checking for the CVE-2012-0152 vulnerability. If this vulnerability is not patched, it is assumed that CVE-2012-0002 is not patched either. This script can do its check without crashing the target.
The way this works follows:
The majority of Microsoft customers have automatic updating enabled and will not need to take any action because this security update will be downloaded and installed automatically. Microsoft customers who have not enabled automatic updating need to check for updates and install this update manually.
See Microsoft Page for more.