CVE-2019-20908: Canonical Ubuntu Linux

Medium severity, CVSS 6.7. EPSS: 0.5% chance of exploitation in the next 30 days.

An issue was discovered in drivers/firmware/efi/efi.c in the Linux kernel before 5.4. Incorrect access permissions for the efivar_ssdt ACPI variable could be used by attackers to bypass lockdown or secure boot restrictions, aka CID-1957a85b0032.

Affected products

• Canonical Ubuntu Linux: version 16.04 only; version 18.04 only
• Linux Linux Kernel: before 5.4 (fixed in 5.4)
• Opensuse Leap: version 15.1 only

Published 2020-07-15. Last modified 2026-06-17.