Failure possibility of Windows KB5012170 Secure Boot DBX update with 0x800f0922 error
On Monday, Microsoft is warning that users might experience a 0x800f0922 error when installing Windows KB5012170 Secure Boot security update on currently supported operating systems for consumers and the enterprise-class Server version.
The problem does not impact the cumulative security updates, monthly rollups, or security-only updates that Microsoft made available on August 9.
Error 0x800f0922 is related strictly to KB5012170, a security update for the Secure Boot DBX (Forbidden Signature Database), a repository that holds revoked signatures for Unified Extensible Firmware Interface (UEFI) bootloaders, Bleeping Computer reports.
A UEFI bootloader operates immediately after the system is turned on and is responsible for launching the UEFI environment with the Secure Boot feature that lets only trusted code be carried out when starting the Windows booting process.
Last week, security researchers from Eclypsium revealed vulnerabilities in three signed third-party bootloaders that can be exploited to bypass the Secure Boot feature and infect the system with malicious code that is difficult to detect and remove.
Microsoft addresses the issue by adding the signatures of the bootloaders above to the Secure Boot DBX so that vulnerable UEFI modules can no longer be loaded.