Researchers at ESET discovered that Microsoft's Secure Boot mechanism has been trivially bypassable for 13 of its 14 years due to unrevoked, vulnerable 'shim' binaries. These legacy shims, originally designed to support Linux, allow attackers to install persistent malicious firmware without needing complex exploits, affecting both Windows and Linux users. The breach highlights a critical failure in Microsoft's certificate revocation process for widely deployed firmware components.
Background
UEFI Secure Boot is a security standard designed to ensure that a device boots using only trusted software, preventing rootkits and other low-level malware from loading during startup. Microsoft manages a list of trusted keys and shims to facilitate cross-platform compatibility, particularly for Linux distributions.
- Source
- Ars Technica
- Published
- Jul 15, 2026 at 06:20 AM
- Score
- 9.0 / 10