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.
NOTE: The following CVSS v3.0 metrics and score provided are preliminary and subject to review.
|Base Score:||7.5||Base Metrics:||AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H|
|Access Vector:||Local network||Attack Complexity:||High|
|Privileges Required:||High||User Interaction:||None|
|Integrity Impact:||High||Availability Impact:||High|
|Oracle Linux version 7 (grub2)||ELSA-2021-0699||2021-03-05|
|Oracle Linux version 7 (grub2)||ELSA-2021-9076||2021-03-02|
|Oracle Linux version 8 (grub2)||ELSA-2021-0696||2021-03-05|
|Oracle Linux version 8 (grub2)||ELSA-2021-9077||2021-03-02|
This page is generated automatically and has not been checked for errors or omissions. For clarification or corrections please contact the Oracle Linux ULN team