Affected: GNU Project GNU GRUB

The GRUB2's shim_lock verifier allows non-kernel files to be loaded on shim-powered secure boot systems. Allowing such files to be loaded may lead to unverified code and modules to be loaded in GRUB2 breaking the secure boot trust-chain.

Affected: Ubuntu:20.04:LTS: grub2-signed, Ubuntu:20.04:LTS: grub2-unsigned, Ubuntu:20.04:LTS: shim, Ubuntu:20.04:LTS: shim-signed, Ubuntu:22.04:LTS: grub2-signed, Ubuntu:22.04:LTS: grub2-unsigned, Ubuntu:22.04:LTS: shim, Ubuntu:22.04:LTS: shim-signed

Daniel Axtens discovered that specially crafted images could cause a heap-based out-of-bonds write. A local attacker could possibly use this to circumvent secure boot protections. (CVE-2021-3695)

Daniel Axtens discovered that specially crafted images could cause out-of-bonds read and write. A local attacker could possibly use this to circumvent secure boot protections. (CVE-2021-3696)

Daniel Axtens discovered that specially crafted images could cause buffer underwrite which allows arbitrary data to be written to a heap. A local attacker could possibly use this to circumvent secure boot protections. (CVE-2021-3697)

It was discovered that GRUB2 configuration files were created with the wrong permissions. An attacker could possibly use this to leak encrypted passwords. (CVE-2021-3981)

Daniel Axtens discovered that specially crafted IP packets could cause an integer underflow and write past the end of a buffer. An attacker could possibly use this to circumvent secure boot protections. (CVE-2022-28733)

Daniel Axtens discovered that specially crafted HTTP headers can cause an out-of-bounds write of a NULL byte. An attacker could possibly use this to corrupt GRUB2's internal data. (CVE-2022-28734)

Julian Andres Klode discovered that GRUB2 shim_lock allowed non- kernel files to be loaded. A local attack could possibly use this to circumvent secure boot protections. (CVE-2022-28735)

Chris Coulson discovered that executing chainloaders more than once caused a use-after-free vul…