The latest Windows 10 fixes, released as part of yesterday's Patch Tuesday, enable protection against the Spectre variant 2 attacks on systems with AMD processors.

Earlier this year, attacks that exploit the processor's speculative execution were published with the names Meltdown and Spectre, prompting a reaction from hardware and software companies . AMD chips are immune to Meltdown but have some vulnerability to the two Spectre variants. Spectre variant 1 requires application-level fixes; variant 2 requires operating system-level alterations.

Both Intel and AMD have released microcode updates to alter their processor behavior to give operating systems the control necessary to protect against Spectre variant 2. Microsoft has been shipping the Intel microcode, along with the operating system changes necessary to use the microcode's new features, for several weeks now; with yesterday's patch, similar protections are now enabled on AMD machines.

The patch is currently only for Windows 10; an equivalent fix for Windows Server 2016 is still undergoing validation and testing.

The operating system changes only take effect when a suitable microcode is installed. AMD has published microcode updates for processors released since 2011, when its Bulldozer architecture made its debut. Presently, the only way to install the microcode is to install a system firmware that includes the updates. Microsoft has the ability to distribute and install microcode updates through Windows Update, and the company started doing this for Intel chips last month, but currently it isn't doing the same for AMD processors.