Some bad (temporary) news. Source: https://twitter.com/epakskape/status/831172683358285824 Source: https://twitter.com/epakskape/status/831178823391535104 So it appears as though Return Flow Guard has been removed from the latest Insider build (15031) because it does not meet Microsoft's expectations for that mitigation at the moment. Whether that means RFG breaking other programs, or the level of security provided by RFG, I don't know right now. But it seems that this is temporary and they will keep working on it. I am not feeling very positive that RFG will make it into Creators Update by April.
Slides from CanSecWest show why RFG has temporarily been scrapped Link: https://www.slideshare.net/CanSecWest/csw2017-weston-miller-csw17mitigatingnativeremotecodeexecution (Pages 19-25) Essentially, a design-level bypass for RFG was discovered. RFG remains a research project. We will most likely see it again on a future Windows 10 build, but unfortunately not on Creators Update 1703.
