Security Experts:

Microsoft Releases More Microcode Patches for Spectre Flaw

Microsoft this week released another round of software and microcode updates designed to address the CPU vulnerability known as Spectre Variant 2.

Microsoft has been releasing software mitigations for the Spectre and Meltdown vulnerabilities since January, shortly after researchers disclosed the flaws.

A new standalone security update (4078407) enables by default the mitigations against Spectre Variant 2 in all supported versions of Windows 10 and Windows Server 2016. Alternatively, advanced users can manually enable these mitigations through registry settings.

The company announced in early March that microcode updates from Intel will be delivered to Windows 10 and Windows Server 2016 users through the Microsoft Update Catalog. The first round of updates covered devices with Intel Skylake processors and the list was later expanded to include Coffee Lake and Kaby Lake CPUs.

Broadwell and Haswell processors have now also been added to the list, which currently includes tens of Intel CPUs across roughly 30 microarchitecture categories. Intel announced the availability of microcode updates for Broadwell and Haswell CPUs in late February.

Meltdown and Spectre allow malicious applications to bypass memory isolation and access sensitive data. Meltdown attacks are possible due to CVE-2017-5754, while Spectre attacks are possible due to CVE-2017-5753 (Variant 1) and CVE-2017-5715 (Variant 2). Meltdown and Spectre Variant 1 can be resolved with software updates, but Spectre Variant 2 requires microcode patches as well.

Last month, Microsoft released out-of-band updates for Windows 7 and Windows Server 2008 R2 to address a serious privilege escalation vulnerability introduced by the Meltdown mitigations.

Related: AMD, Microsoft Release Spectre Patches

Related: Microsoft Patches for Meltdown Introduced Severe Flaw

Related: Intel Shares Details on New CPUs With Spectre, Meltdown Protections

view counter
Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.