Summary
Vulnerabilities in System Management Mode (SMM) and more general UEFI applications/drivers (DXE) are receiving increased attention from security researchers. Over the last 9 months, the Binarly efiXplorer team disclosed 42 high-impact vulnerabilities related to SMM and DXE firmware components. But newer platforms have significantly increased the runtime mitigations in the UEFI firmware execution environment (including SMM). The new Intel platform firmware runtime mitigations reshaped the attack surface for SMM/DXE with new Intel Hardware Shield technologies applied below-the-OS.