One of the Windows Updates issued this month (May 2021) patches a serious security issue with HTTP.SYS:
https://msrc.microsoft.com/update-guide ... 2021-31166
Virtual Radar Server uses HTTP.SYS. If you are running VRS on Windows, and in particular if you have put your VRS instance onto the public Internet, then you should make sure that you apply the latest Windows Updates to get HTTP.SYS patched.