Security Experts:

Microsoft Suspends CPU Flaw Patches for AMD Devices

Microsoft Will Not Deliver Security Updates to Devices With Incompatible Antiviruses

Users whose computers have AMD processors no longer receive the recent Windows updates designed to patch the Meltdown and Spectre vulnerabilities, and Microsoft has warned that some systems may not receive upcoming security updates if the antivirus running on them has not set a specific registry key.

Several individuals whose devices are powered by some AMD processors, particularly older models, complained that they had been unable to boot Windows 10 after installing KB4056892, an update released by Microsoft in response to flaws affecting Intel, AMD and ARM processors.

Many of those affected said their operating system froze during boot. Those who managed to restore their systems by reverting to a previous state needed to quickly disable automatic updates to prevent the patch from being reinstalled.

Some of the impacted users pointed out that since the risk of attacks against AMD CPUs is said to be low, they can wait for proper updates from Microsoft.

Microsoft has confirmed the issue, explaining that “some AMD chipsets do not conform to the documentation previously provided to Microsoft to develop the Windows operating system mitigations to protect against the chipset vulnerabilities known as Spectre and Meltdown.”

The tech giant has decided to temporarily pause Windows updates to devices with impacted AMD processors. For those who have already installed the updates and are experiencing problems, Microsoft has provided some recommendations on how to fix the issue.

Microsoft’s advice for Windows 10 users includes starting the computer in safe mode and uninstalling recent updates, or restoring the system to an earlier point. Several users have complained, however, that they get an error when attempting to restore the system.

In addition to causing problems to Windows, the Spectre and Meltdown updates from Microsoft also break some applications, including the PulseSecure VPN and an Asus utility.

Security updates will not be delivered to devices with incompatible antiviruses

When Microsoft first released the updates designed to prevent Spectre and Meltdown attacks, the company warned that it had identified compatibility issues with some security products. It informed users that if they had not been offered the security updates, it may have been due to the failure of their antivirus to create a specific registry key.

Microsoft later also informed users that they may not receive any future security updates if their antivirus vendor does not address the problem.

Researcher Kevin Beaumont has been keeping track of which security vendors have implemented this requirement. As of Monday, a majority of firms had either released automatic fixes or made available instructions on how to manually create the required registry. The remaining vendors are working on fixes.

Microsoft noted that users who don’t rely on any antivirus will also need to manually create the registry key.

The role of the registry key is to prevent blue screen of death (BSOD) errors triggered due to compatibility issues when security products make unsupported calls to the Windows kernel memory. Microsoft says the requirement for the registry key will remain in place until the company is confident that a majority of consumers will not experience crashes due to the security updates.

Related: Qualcomm Working on Mitigations for Spectre, Meltdown

Related: Lawsuits Filed Against Intel Over CPU Vulnerabilities

Related: Industry Reactions to Meltdown, Spectre Attacks

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.