CVE-2020-15705
GRUB2: avoid loading unsigned kernels when GRUB is booted directly under secureboot without shim
MEDIUM 6.4
At a glance
- Source
- NVD
- EPSS
- EPSS 1.39 % · percentile 72 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- canonical
- NVD status
- Modified
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.
Weaknesses (CWE)
- CWE-347 — Improper Verification of Cryptographic Signature
References
- https://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/
- https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypass
- http://ubuntu.com/security/notices/USN-4432-1
- https://www.debian.org/security/2020-GRUB-UEFI-SecureBoot
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200011
- https://access.redhat.com/security/vulnerabilities/grub2bootloader
- https://www.suse.com/c/suse-addresses-grub2-secure-boot-issue/
- https://www.suse.com/support/kb/doc/?id=000019673
- https://www.openwall.com/lists/oss-security/2020/07/29/3
- https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html
- http://www.openwall.com/lists/oss-security/2020/07/29/3
- https://security.netapp.com/advisory/ntap-20200731-0008/
- https://usn.ubuntu.com/4432-1/
- http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00067.html
- http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00069.html
- http://www.openwall.com/lists/oss-security/2021/03/02/3
- https://security.gentoo.org/glsa/202104-05
- http://www.openwall.com/lists/oss-security/2021/09/17/2
- http://www.openwall.com/lists/oss-security/2021/09/17/4
- http://www.openwall.com/lists/oss-security/2021/09/21/1
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.4 | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H | canonical |
| CVSS 3.1 | MEDIUM 6.4 | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H | NVD · security@ubuntu.com (Secondary) |
| CVSS 3.1 | MEDIUM 6.4 | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H | NVD · nvd@nist.gov (Primary) |
| CVSS 2.0 | MEDIUM 4.4 | AV:L/AC:M/Au:N/C:P/I:P/A:P | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2020-7691
- GCVE · GCVE-0-2020-15705
CERT-FR advisories
- CERTFR-2022-AVI-267 — Multiples vulnérabilités dans Juniper Networks Junos Space · cert.ssi.gouv.fr
- CERTFR-2021-AVI-172 — Multiples vulnérabilités dans GRUB · cert.ssi.gouv.fr
- CERTFR-2020-AVI-485 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2020-AVI-477 — Multiples vulnérabilités dans Grub2 · cert.ssi.gouv.fr
- CERTFR-2020-AVI-476 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*≤ 2.04cpe:2.3:a:redhat:enterprise_linux_atomic_host:-:*:*:*:*:*:*:*cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*cpe:2.3:o:suse:suse_linux_enterprise_server:11:*:*:*:*:*:*:*cpe:2.3:o:suse:suse_linux_enterprise_server:12:*:*:*:*:*:*:*cpe:2.3:o:suse:suse_linux_enterprise_server:15:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_10:1709:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_10:1903:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_server_2016:1903:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_server_2016:1909:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:*cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Ubuntu · grub2 in Ubuntu | affected 20.04 LTS < 2.04-1ubuntu26.1 ; affected 18.04 LTS < 2.02-2ubuntu8.16 ; affected 16.04 LTS < 2.02~beta2-36ubuntu3.26 ; affected 14.04 ESM < 2.02~beta2-9ubuntu1.20 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |