CVE-2021-3418

medium
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
5.5

Description

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 grub2 versions prior to 2.06 and upstream and distributions using the shim_lock mechanism.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-3418

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-3418.html

OS impact

OSVersionStatusFixed in
arch archaffected
suse slesaffected
debian debianbookwormfixed0
debian debianbullseyefixed0
debian debianforkyfixed0
debian debiansidfixed0
debian debiantrixiefixed0

References

Verify integrity in audit chain (admin only). AS-IS.