CVE-2020-14372: High severity centos grub2-pc-modules vulnerability
A flaw was found in grub2 in versions prior to 2.06, 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.
Other sources
GRUB2 enables the use of the command acpi even when secure boot is signaled by the firmware. An attacker with local root privileges to can drop a small SSDT in /boot/efi and modify grub.cfg to instruct grub to load said SSDT. The SSDT then gets run by the kernel and it overwrites the kernel lockdown configuration enabling the attacker to load unsigned kernel modules and kexec unsigned code.
— Red Hat
Affected Software
Remediation
Event History
Frequently Asked Questions
What is CVE-2020-14372?
CVE-2020-14372 is a vulnerability in grub2 prior to version 2.06 that enables the usage of the ACPI command when Secure Boot is enabled.
What is the severity of CVE-2020-14372?
The severity of CVE-2020-14372 is high with a CVSS score of 7.5.
How does CVE-2020-14372 affect Red Hat Enterprise Linux?
CVE-2020-14372 affects Red Hat Enterprise Linux versions 7.0, 7.2, 7.3, 7.4, 7.6, 7.7, 8.0, 8.1, and 8.2.
How can I fix CVE-2020-14372?
To fix CVE-2020-14372, update grub2 to version 2.06.
Where can I find more information about CVE-2020-14372?
You can find more information about CVE-2020-14372 at the following references: [Reference 1](https://access.redhat.com/security/vulnerabilities/RHSB-2021-003), [Reference 2](https://bugzilla.redhat.com/show_bug.cgi?id=1873150), [Reference 3](https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZWZ36QK4IKU6MWDWNOOWKPH3WXZBHT2R/).