Does a virtual machine inherit the security features of its host?

Question

I have a question about virtual machines.

If I run a Windows 7 or 10 virtual machine inside a Linux host, will the Windows machine inherit the security of the Linux host, or should I take all the security measures in Windows just like a hardware machine?

What if I run Linux virtual machine on a Windows host, does it inherit the vulnerabilities of the Windows host?

Thanks.

Answer 1

There are two categories of threats:

• those that attack from a network (trying to connect to open ports and the like)
• those that attack from inside (usually through your browser or e-mail).

Running in a VM offers some protection against the first kind (but then being behind your home router also does...). For the second kind, your Windows machine is exposed to essentially the same threats as if it were running on "bare metal" (and same for Linux VM on Linux host).

Then what matters are the risks and the consequences.

• If you use the VM as your regular working machine then it must be protected like a regular working machine running on the hardware.
• If you have only very specific uses (testing a Windows version of something for instance...), hardly use the web on it (and only on safe sites) and can easily rebuild the machine(*), then you can lower your protections (but don't give the VM access to your whole host file hierarchy through shared folders...)

(*) ideally you start from a fresh machine each time...

Answer 2

Treat your virtual machines the same as physical machines in every way (including security) when it comes to software. They will not, as a rule, inherit any security measures or configuration from the host machine.