CVE-2020-15705 | BDVDB-2026-139604 Detail
Ubuntugrub2 in Ubuntu
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.
Impact#
Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact high. Attack vector: local.
Weaknesses#
- 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
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.