CVE-2021-20225
Published: 2 March 2021
A flaw was found in grub2 in versions prior to 2.06. The option parser allows an attacker to write past the end of a heap-allocated buffer by calling certain commands with a large number of specific short forms of options. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
From the Ubuntu Security Team
It was discovered that the option parser in GRUB 2 contained a heap overflow vulnerability. A local attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions.
Notes
Author | Note |
---|---|
sbeattie | grub2-unsigned will contain fixes and supersede grub2, which will contain only BIOS grub bits. |
Priority
Status
Package | Release | Status |
---|---|---|
grub2 Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
(does not affect Secure Boot)
|
focal |
Not vulnerable
(does not affect Secure Boot)
|
|
jammy |
Not vulnerable
(does not affect Secure Boot)
|
|
kinetic |
Not vulnerable
(does not affect Secure Boot)
|
|
lunar |
Not vulnerable
(does not affect Secure Boot)
|
|
mantic |
Not vulnerable
(does not affect Secure Boot)
|
|
trusty |
Not vulnerable
(does not affect Secure Boot)
|
|
upstream |
Needs triage
|
|
xenial |
Not vulnerable
(does not affect Secure Boot)
|
|
grub2-signed Launchpad, Ubuntu, Debian |
bionic |
Released
(1.167~18.04.5)
|
focal |
Released
(1.167.2)
|
|
groovy |
Released
(1.167.2)
|
|
hirsute |
Released
(1.164)
|
|
impish |
Released
(1.169)
|
|
jammy |
Not vulnerable
(1.180)
|
|
kinetic |
Not vulnerable
(1.185)
|
|
lunar |
Not vulnerable
(1.192)
|
|
mantic |
Not vulnerable
(1.193)
|
|
trusty |
Needed
|
|
upstream |
Needs triage
|
|
xenial |
Released
(1.164)
|
|
grub2-unsigned Launchpad, Ubuntu, Debian |
bionic |
Released
(2.04-1ubuntu44.1.2)
|
focal |
Released
(2.04-1ubuntu44.2)
|
|
groovy |
Released
(2.04-1ubuntu44.2)
|
|
hirsute |
Released
(2.04-1ubuntu42)
|
|
impish |
Released
(2.04-1ubuntu45)
|
|
jammy |
Not vulnerable
(2.06-2ubuntu7)
|
|
kinetic |
Not vulnerable
(2.06-2ubuntu12)
|
|
lunar |
Not vulnerable
(2.06-2ubuntu16)
|
|
mantic |
Not vulnerable
(2.06-2ubuntu17)
|
|
trusty |
Does not exist
|
|
upstream |
Needs triage
|
|
xenial |
Released
(2.04-1ubuntu42)
|
Severity score breakdown
Parameter | Value |
---|---|
Base score | 6.7 |
Attack vector | Local |
Attack complexity | Low |
Privileges required | High |
User interaction | None |
Scope | Unchanged |
Confidentiality | High |
Integrity impact | High |
Availability impact | High |
Vector | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |