New UEFI flaw enables pre-boot attacks on motherboards from Gigabyte, MSI, ASUS, ASRock

Researchers disclosed UEFI firmware flaws in select ASUS, Gigabyte, MSI, and ASRock motherboards that can falsely report DMA protections as enabled while failing to initialize the IOMMU, enabling physical pre-boot DMA attacks via malicious PCIe devices. The issue (multiple CVEs) can allow reading or modifying RAM before the OS loads, prompted vendor advisories and firmware updates, and has caused Riot Games' Vanguard anti-cheat to block affected systems from launching Valorant until mitigations are applied.