Several widely used open-source bootloaders, including GRUB2 for Linux, U-Boot, and Barebox, have been found to contain critical vulnerabilities
that could allow attackers to execute arbitrary code and gain control over systems. Microsoft, leveraging artificial intelligence, identified these flaws, saving significant time in the process.
Microsoft’s Threat Intelligence team disclosed 20 vulnerabilities affecting multiple open-source bootloaders. These flaws impact all operating systems that rely on Unified Extensible Firmware Interface (UEFI) Secure Boot, as well as Internet of Things (IoT) devices. Bootloaders play a crucial role in system security, as they are responsible for loading the operating system after the firmware (UEFI or BIOS). Exploiting these vulnerabilities could lead to stealthy bootkit infections, allowing attackers to bypass security mechanisms such as BitLocker.
Microsoft warns that bootkit installations can have severe consequences, granting threat actors full control over a device. This could enable them to manipulate the boot process, take over the operating system, compromise other devices on the network, and engage in further malicious activities. However, while these vulnerabilities are serious, their exploitation is somewhat limited, as attackers would likely need physical access to the targeted system.
The discovery of these flaws was accelerated by AI, specifically Microsoft's Security Copilot system. Researchers used AI to analyze bootloader functionalities, focusing on networks, filesystems, and cryptographic signatures. By narrowing their investigation to filesystems, they were able to identify an exploitable integer overflow vulnerability. According to Microsoft, this AI-driven approach saved researchers nearly a week’s worth of manual review time, demonstrating the potential for AI to enhance cybersecurity efficiency.
Of the 20 identified vulnerabilities, 11 affect GRUB2, five impact Barebox, and four were found in U-Boot. Microsoft disclosed the flaws to the respective maintainers, and security updates addressing these vulnerabilities were released in February 2025.
Found this article interesting? Follow us on X(Twitter) and FaceBook to read more exclusive content we post.
