CVE-2021-3418

A flaw was found in grub. If certificates that signed grub are installed into db, grub can be booted directly. It will then boot any kernel without signature validation. The booted kernel will think it was booted in secureboot mode and will implement lockdown, yet it could have been tampered. This flaw is a reintroduction of CVE-2020-15705 and only affects upstream and distributions using the shim_lock mechanism.

Red Hat Enterprise Linux 7 and 8 are not affected by this issue, as both versions doesn't ship the shim_lock mechanism.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.