Integer overflows were discovered in the functions grub_cmd_initrd and grub_initrd_init in the efilinux component of GRUB2, as shipped in Debian, Red Hat, and Ubuntu (the functionality is not included in GRUB2 upstream), leading to a heap-based buffer overflow. These could be triggered by an extremely large number of arguments to the initrd command on 32-bit architectures, or a crafted filesystem with very large files on any architecture. An attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. This issue affects GRUB2 version 2.04 and prior versions.

A vulnerability in the firmware of the Cisco UCS C-Series Rack Servers could allow an authenticated, physical attacker to bypass Unified Extensible Firmware Interface (UEFI) Secure Boot validation checks and load a compromised software image on an affected device. The vulnerability is due to improper validation of the server firmware upgrade images. An attacker could exploit this vulnerability by installing a server firmware version that would allow the attacker to disable UEFI Secure Boot. A successful exploit could allow the attacker to bypass the signature validation checks that are done by UEFI Secure Boot technology and load a compromised software image on the affected device. A compromised software image is any software image that has not been digitally signed by Cisco.

Multiple integer overflows in the Pre-EFI Initialization (PEI) boot phase in the Capsule Update feature in the UEFI implementation in EDK2 allow physically proximate attackers to bypass intended access restrictions by providing crafted data that is not properly handled during the coalescing phase.

Integer overflow in the Drive Execution Environment (DXE) phase in the Capsule Update feature in the UEFI implementation in EDK2 allows physically proximate attackers to bypass intended access restrictions via crafted data.

A potential security vulnerability with pre-boot DMA may allow unauthorized UEFI code execution using open-case attacks. This industry-wide issue requires physically accessing internal expansion slots with specialized hardware and software tools to modify UEFI code in memory. This affects HP Intel-based Business PCs that support Microsoft Windows 10 Kernel DMA protection. Affected versions depend on platform (prior to 01.04.02; or prior to 02.04.01; or prior to 02.04.02).

In Phoenix SCT WinFlash 1.1.12.0 through 1.5.74.0, the included drivers could be used by a malicious Windows application to gain elevated privileges. Adverse impacts are limited to the Windows environment and there is no known direct impact to the UEFI firmware. This was fixed in late June 2019.

HP has identified a security vulnerability with some versions of Workstation BIOS (UEFI Firmware) where the runtime BIOS code could be tampered with if the TPM is disabled. This vulnerability relates to Workstations whose TPM is enabled by default.

HP has identified a security vulnerability with some versions of Workstation BIOS (UEFI Firmware) where the runtime BIOS code could be tampered with if the TPM is disabled. This vulnerability relates to Workstations whose TPM is disabled by default.

The Linux kernel, as used in Ubuntu 18.10 and when booted with UEFI Secure Boot enabled, allows privileged local users to bypass intended Secure Boot restrictions and execute untrusted code by loading arbitrary kernel modules. This occurs because a modified kernel/module.c, in conjunction with certain configuration options, leads to mishandling of the result of signature verification.

Existing UEFI setting restrictions for DCI (Direct Connect Interface) in 5th and 6th generation Intel Xeon Processor E3 Family, Intel Xeon Scalable processors, and Intel Xeon Processor D Family allows a limited physical presence attacker to potentially access platform secrets via debug interfaces.