Ubuntu.comUB:CVE-2020-15705CVE-2020-15705
CVSS2
Attack Vector
LOCAL
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:M/Au:N/C:P/I:P/A:P
CVSS3
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
33.3%
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.
Bugs
Notes
| Author | Note |
|---|---|
| alexmurray | grub2-signed is not supported in Ubuntu 12.04 ESM (precise/esm) and so marking the priority for grub2 in this release as low |
| OS | Version | Architecture | Package | Version | Filename |
|---|---|---|---|---|---|
| ubuntu | 18.04 | noarch | grub2 | < 2.02-2ubuntu8.16 | UNKNOWN |
| ubuntu | 20.04 | noarch | grub2 | < 2.04-1ubuntu26.1 | UNKNOWN |
| ubuntu | 14.04 | noarch | grub2 | < 2.02~beta2-9ubuntu1.20 | UNKNOWN |
| ubuntu | 16.04 | noarch | grub2 | < 2.02~beta2-36ubuntu3.26 | UNKNOWN |
| ubuntu | 18.04 | noarch | grub2-signed | < 1.93.18 | UNKNOWN |
| ubuntu | 20.04 | noarch | grub2-signed | < 1.142.3 | UNKNOWN |
| ubuntu | 14.04 | noarch | grub2-signed | < 1.34.22 | UNKNOWN |
| ubuntu | 16.04 | noarch | grub2-signed | < 1.66.26 | UNKNOWN |
| ubuntu | 16.04 | noarch | grub2-unsigned | < any | UNKNOWN |
References
launchpad.net/bugs/cve/CVE-2020-15705
lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html
nvd.nist.gov/vuln/detail/CVE-2020-15705
security-tracker.debian.org/tracker/CVE-2020-15705
ubuntu.com/security/notices/USN-4432-1
wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypass
www.cve.org/CVERecord?id=CVE-2020-15705
www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/
www.openwall.com/lists/oss-security/2020/07/29/3
Related
CVSS2
Attack Vector
LOCAL
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:M/Au:N/C:P/I:P/A:P
CVSS3
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
33.3%