Ubuntu.comUB:CVE-2020-15706CVE-2020-15706
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
61.9%
GRUB2 contains a race condition in grub_script_function_create() leading to
a use-after-free vulnerability which can be triggered by redefining a
function whilst the same function is already executing, leading to
arbitrary code execution and secure boot restriction bypass. This issue
affects GRUB2 version 2.04 and prior versions.
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 |
| sbeattie | 809f3a268 script: Avoid a use-after-free when redefining a function during execution |
| 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-2020-15706
lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html
nvd.nist.gov/vuln/detail/CVE-2020-15706
security-tracker.debian.org/tracker/CVE-2020-15706
ubuntu.com/security/notices/USN-4432-1
wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypass
www.cve.org/CVERecord?id=CVE-2020-15706
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
61.9%