CVE-2020-15705

GRUB2: avoid loading unsigned kernels when GRUB is booted directly under secureboot without shim

MEDIUM
6.4
CVSS Score
Published: July 29, 2020 at 05:45 PM UTC
Updated: June 17, 2026 at 02:57 AM UTC
15 products affected across 8 vendorsDebian LinuxWindows Server 2016Windows Server 2019

Using grub2 in Ubuntu by Ubuntu?

Get instant alerts when new vulnerabilities affect grub2 in Ubuntu - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM6.4
Exploit prediction
EPSS 1%

Description

GRUB2 fails to validate kernel signature when booted directly without shim, allowing secure boot to be bypassed. This only affects systems where the kernel signing certificate has been imported directly into the secure boot database and the GRUB image is booted directly without the use of shim. This issue affects GRUB2 version 2.04 and prior versions.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

References (20)

Vendor Advisoryx_refsource_SUSEMailing ListThird Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00067.html
Vendor Advisoryx_refsource_SUSEMailing ListThird Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00069.html
Vendor Advisoryx_refsource_UBUNTUThird Party Advisory
http://ubuntu.com/security/notices/USN-4432-1
Mailing Listx_refsource_MLISTThird Party Advisory
http://www.openwall.com/lists/oss-security/2020/07/29/3
Mailing Listx_refsource_MLISTThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/03/02/3
Mailing Listx_refsource_MLISTThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/17/2
Mailing Listx_refsource_MLISTThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/17/4
Mailing Listx_refsource_MLISTThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/21/1

CVSS

6.4MEDIUMcanonical
Attack Vector
LOCAL
Complexity
HIGH
Privileges
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-347

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card