CVE-2021-3418

mediumpriority · track · 26EPSS 0.005 · 40 %ileEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.47% (40th) EPSS
CVSS 4.4 · medium
Is it mine?
24 products
Check your exposure
Who says so?
3 sources
cnnvd · enisa_euvd · fstec_bdu

EPSS · scored 2026-10-27

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.

01

cvss

Technical severity, 0–10. One row per scoring source.

6.4
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04.4mediumAV:L/AC:M/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 3.4 · impact 6.4
v3.16.4mediumCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 0.5 · impact 5.9
v3.16.4mediumAV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.15.9mediumCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
02

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-281USCWE-281USCWE-347US
03

affected products (24)

Products and version ranges known to be affected.

showing 20 of 24
04

also known as (4)

Other names and identifiers for this entity.

05

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bduNVDCVE.orgMITRE
published 2021-03-15modified 2026-06-17
06

references (8)

External citations — patches, advisories, analysis.

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