We use Oracle VirtualBox OSE as a part of our custom virtualization infrastructure, and compile it on our CI servers. One of numerous compilation parameters you can add into LocalConfig.kmk, custom configuration file, is VBOX_WITH_HARDENING = 0
, which obviously means compiling VirtualBox without Hardening. Also, you could not turn it on, if you compile it yourself.
I could not find in official build instructions, what in "hardening" on the "low-level", as far as I understood it's a some security patch, increasing guest OS-es protection against exploits. However, it still leaves a lot of questions. What is it physically, a driver, a patch, an application? Why Hardening sources are not included in VirtualBox OSE, an open-source product? I mean, how is it possible with the open-source license, which was derived from Sun Microsystems? And the main question, is it possible to compile VirtualBox OSE with Hardening?