Microsoft's Latest Security Update Causes Problems On Dual-boot Windows, Linux Systems

(RTTNews) - Microsoft (MSFT) released updates to fix a vulnerability that unintentionally caused problems for dual-boot PCs running Windows and various Linux distributions during its latest Patch Tuesday event.

According to Ars Technica, the update was designed to address the GRUB2 Secure Boot bypass vulnerability identified as CVE-2022-2601, which posed potential risks to Windows security. Discovered in 2022, this vulnerability could enable hackers to manipulate GRUB, an open-source boot loader, thereby circumventing the Secure Boot feature.

Microsoft noted in an advisory released last week that "the vulnerability assigned to this CVE is in the Linux GRUB2 boot loader, a boot loader designed to support Secure Boot on systems that are running Linux." The patch was not intended for dual-boot systems with Windows and Linux; however, it was mistakenly distributed to users of these configurations.

Consequently, affected PCs were unable to boot into Linux with Secure Boot enabled, displaying an error message stating, "Verifying shim SBAT data failed: Security Policy Violation. Something has gone seriously wrong: SBAT self-check failed: Security Policy Violation."

Ars Technica reported that the issue seems to have affected distributions such as Ubuntu, Debian, Linux Mint, Zorin OS, and Puppy Linux.

Users attempted various solutions, but ultimately, disabling Secure Boot, installing the latest version of their preferred Linux distribution, and then re-enabling Secure Boot was the only viable fix. Microsoft has not provided any comments regarding the problems caused by its update, but Ubuntu users can employ a workaround by disabling Secure Boot in the BIOS settings and removing Microsoft's SBAT policy using a terminal.