Lucene search

[email protected]NVD:CVE-2021-3418

HistoryMar 15, 2021 - 10:15 p.m.

CVE-2021-3418

2021-03-1522:15:13

CWE-281

[email protected]

web.nvd.nist.gov

certificates

grub

kernel boot

signature validation

secureboot

tampered

cve-2021-3418

cve-2020-15705

grub2

upstream

distributions

shim_lock

CVSS2

4.4

Attack Vector

LOCAL

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:L/AC:M/Au:N/C:P/I:P/A:P

CVSS3

6.4

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS

0.001

Percentile

31.4%

JSON

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.