Red Hat Security Advisory 2015-2401-01 – The grub2 packages provide version 2 of the Grand Unified Bootloader, a highly configurable and customizable bootloader with modular architecture. The packages support a variety of kernel formats, file systems, computer architectures, and hardware devices. It was discovered that grub2 builds for EFI systems contained modules that were not suitable to be loaded in a Secure Boot environment. An attacker could use this flaw to circumvent the Secure Boot mechanisms and load non-verified code. Attacks could use the boot menu if no password was set, or the grub2 configuration file if the attacker has root privileges on the system.