VU#434994: Multiple race conditions due to TOCTOU flaws in various UEFI Implementations

Overview Multiple Unified Extensible Firmware Interface (UEFI) implementations are vulnerable to code execution in System Management Mode (SMM) by an attacker who gains administrative privileges on the local machine. An attacker can corrupt the memory using Direct Memory Access (DMA) timing attacks that can lead to code execution. These threats are collectively referred to as RingHopper attacks. Description The UEFI standard provides an open specification that defines a software interface between an operating system (OS) and the device hardware on...