Microsoft (re-) enabled the possibility to import microcode updates with IBC patches against Specter as an update of the operating system – for the time being only for Core i-6000 (Skylake). Although older Windows versions were able to obtain microcode updates for processors via Windows Update, Microsoft had previously not used this function for patches against the Specter V2 vulnerability (CVE-2017-5017). Instead, Microsoft forced the owners of affected systems to install the microcode updates via BIOS update. This is much more complicated than a Windows update, quite apart from the fact that not all manufacturers of affected systems even provide BIOS updates, especially for older computers or if the manufacturer does not exist anymore. Now Microsoft is providing the optional update KB4090007 in version V1.001 via Microsoft Update Catalog, which contains the Intel Microcode Update Revision 0xC2 for processors of the type Intel Core i-6000 (Skylake).
Microsoft promises on the support website for KB4090007, that later also microcode (μCode) updates for other processor types to follow. In the meantime, after the withdrawal of the first updates on January 22, Intel has also released new microcode updates for the most important processor series since 2013 – but so far only for PC manufacturers.