CVE-2020-15705

moderate-risk
Published 2020-07-29

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.

Do I need to act?

-
0.02% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
6
CVSS 6.4/10 Medium
LOCAL / HIGH complexity

Affected Products (20)

Affected Vendors

Debian Redhat Microsoft Gnu Suse Canonical Opensuse

References (40)

Mailing List http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00067.html
Mailing List http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00069.html
Third Party Advisory http://ubuntu.com/security/notices/USN-4432-1
Mailing List http://www.openwall.com/lists/oss-security/2020/07/29/3
Mailing List http://www.openwall.com/lists/oss-security/2021/03/02/3
Mailing List http://www.openwall.com/lists/oss-security/2021/09/17/2
Mailing List http://www.openwall.com/lists/oss-security/2021/09/17/4
Mailing List http://www.openwall.com/lists/oss-security/2021/09/21/1
Third Party Advisory https://access.redhat.com/security/vulnerabilities/grub2bootloader
Issue Tracking https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html
Patch https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200011
Third Party Advisory https://security.gentoo.org/glsa/202104-05
Third Party Advisory https://security.netapp.com/advisory/ntap-20200731-0008/
Third Party Advisory https://usn.ubuntu.com/4432-1/
Third Party Advisory https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypass
Third Party Advisory https://www.debian.org/security/2020-GRUB-UEFI-SecureBoot
Third Party Advisory https://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/
Mailing List https://www.openwall.com/lists/oss-security/2020/07/29/3
Third Party Advisory https://www.suse.com/c/suse-addresses-grub2-secure-boot-issue/
Third Party Advisory https://www.suse.com/support/kb/doc/?id=000019673
and 20 more references
40
/ 100
moderate-risk
Severity 17/34 · Moderate
Exploitability 0/34 · Minimal
Exposure 23/34 · High