Windows 10 and Spectrum Fault, deploy KB4078407 and KB4091666

Microsoft offers two new Windows 10 updates named KB4078407 and KB4091666. They bring corrections supposed to mitigate the fault “Spectrum variant 2”.

Windows 10 and Spectrum Fault, deploy KB4078407 and KB4091666, Windows 10 and Spectrum Fault, deploy KB4078407 and KB4091666, Optocrypto

Windows 10 and Spectrum Fault, deploy KB4078407 and KB4091666

The correction of the Meltdown and Spectre hardware bugs revealed at the beginning of the year, turned out to be much more complex than expected. For several months we have had a succession of updates, new BIOSes, and new firmware. After several patches already offered through the Windows Update service, Microsoft is deploying a new set of updates for Windows 10 users.

The two “firmware” updates KB4078407 and KB4091666 focus on the Spectrum Variant 2 vulnerability, which many thoughts was virtually impossible to exploit.

Windows 10 and KB4078407 / KB4091666, details

KB4078407 is an exclusive patch to Windows 10 however it is not the absolute weapon. Redmond says firmware patches from hardware vendors are also required. This update only protects systems on the “software” side. For more comprehensive protection, additional mitigation measures by manufacturers are required.

You can download KB4078407 manually from the giant’s Catalog Update service. Please note that we are before an update classified “critical”

KB4091666 targets the very first version of Windows 10, v1507. This update is listed as an Intel firmware update. The information is important because it indicates that you need an Intel processor to take advantage of it.

Microsoft specifies:

“This update is a standalone update available through the Microsoft Update catalog. It is designed for Windows 10 Release To Market (RTM). This update also includes Intel firmware updates that were already released at the time of Release To Manufacturing (RTM).

Like KB4078407, you can also download KB4091666 from the giant’s Catalog Update service.

Finally, Microsoft has also released revised firmware updates for other versions of Windows 10. For example, we have:

  • KB4090007 for Windows 10 Fall Creators Update
  • KB4091663 for Windows 10 Creators Update
  • KB4091664 for Windows 10 Anniversary Update

These new versions support other processors than those targeted by early releases. We have for example the management of chips

  • Broadwell DE A1,
  • Broadwell DE V1,
  • Broadwell DE V2, V3,
  • Broadwell DE Y0,
  • Broadwell H 43e,
  • Broadwell U / Y,
  • Broadwell Xeon E3,
  • Haswell (including H, S),
  • Xeon E3,
  • Haswell Perf Halo,
  • Haswell Server E, EP, EP4S,
  • Haswell ULT