Affected: grub2, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4

A flaw was found in command/gpg. In some scenarios, hooks created by loaded modules are not removed when the related module is unloaded. This flaw allows an attacker to force grub2 to call the hooks once the module that registered it was unloaded, leading to a use-after-free vulnerability. If correctly exploited, this vulnerability may result in arbitrary code execution, eventually allowing the attacker to bypass secure boot protections.

grub2: grub-core/gettext: Integer overflow leads to Heap OOB Write and Read. grub2: fs/ufs: OOB write in the heap grub2: command/gpg: Use-after-free due to hooks not being removed on module unload grub2: UFS: Integer overflow may lead to heap based out-of-bounds write when handling symlinks grub2: commands/dump: The dump command is not in lockdown when secure boot is enabled

security update for grub2