CVE-2019-20908
kernel: lockdown: bypass through ACPI write via efivar_ssdt
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · August 19, 2019
Updated · June 28, 2026
Description
A flaw was found in how the ACPI table loading through the EFI variable (and the related efivar_ssdt boot option) was handled when the Linux kernel was locked down. This flaw allows a (root) privileged local user to circumvent the kernel lockdown restrictions. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Statement
This issue is rated as having Moderate impact because of the privileges required for exploitation.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 6.4CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
CWE-284 · Improper Access Control