PT-2020-6588 · Grub2+10 · Grub2+10

Marco Benatto

+1

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Published

2020-08-27

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Updated

2025-08-13

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CVE-2020-14372

CVSS v3.1

7.5

High

VectorAV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
Name of the Vulnerable Software and Affected Versions grub2 versions prior to 2.06
Description A flaw was found in grub2 where it incorrectly enables the usage of the ACPI command when Secure Boot is enabled. This flaw allows an attacker with privileged access to craft a Secondary System Description Table (SSDT) containing code to overwrite the Linux kernel lockdown variable content directly into memory. The table is further loaded and executed by the kernel, defeating its Secure Boot lockdown and allowing the attacker to load unsigned code. The highest threat from this vulnerability is to data confidentiality and integrity, as well as system availability.
Recommendations For versions prior to 2.06, update to version 2.06 or later to resolve the issue. As a temporary workaround, consider disabling the usage of ACPI commands when Secure Boot is enabled until a patch is available. Restrict access to the SSDT table to minimize the risk of exploitation. Avoid using the ACPI command in the grub2 configuration file until the issue is resolved.

Exploit

Fix

Incomplete List of Disallowed Inputs

Weakness Enumeration

Related Identifiers

ALSA-2021:1734
ALSA-2021_1734
ALT-PU-2021-1969
ALT-PU-2021-3464
AZL-6460
BDU:2022-00326
CESA-2021_0696
CESA-2021_1734
CESA-2021_2566
CVE-2020-14372
DSA-4867-1
ELSA-2021-0696
ELSA-2021-0699
ELSA-2021-9076
ELSA-2021-9077
MGASA-2021-0315
OESA-2021-1095
OPENSUSE-SU-2021:0462-1
OPENSUSE-SU-2021_0462-1
RHSA-2021:0696
RHSA-2021:0697
RHSA-2021:0698
RHSA-2021:0699
RHSA-2021:0700
RHSA-2021:0701
RHSA-2021:0702
RHSA-2021:0703
RHSA-2021:0704
RHSA-2021:1734
RHSA-2021:2566
RHSA-2021:2790
RHSA-2021:3675
RHSA-2021_0696
RHSA-2021_0699
RHSA-2021_1734
RHSA-2021_2566
RLSA-2021:1734
RLSA-2021:2566
RLSA-2021_2566
SUSE-SU-2021:0679-1
SUSE-SU-2021:0681-1
SUSE-SU-2021:0682-1
SUSE-SU-2021:0683-1
SUSE-SU-2021:0684-1
SUSE-SU-2021:0685-1
SUSE-SU-2021:14659-1
SUSE-SU-2021_0679-1
SUSE-SU-2021_0681-1
SUSE-SU-2021_0682-1
SUSE-SU-2021_0683-1
SUSE-SU-2021_0684-1
SUSE-SU-2021_0685-1
SUSE-SU-2021_14659-1
USN-4992-1

Affected Products

Alt Linux
Almalinux
Astra Linux
Centos
Linuxmint
Red Hat
Red Os
Rocky Linux
Suse
Ubuntu
Grub2