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-signed Launchpad, Ubuntu, Debian |
hirsute |
Released
(1.164)
|
| bionic |
Released
(1.167~18.04.5)
|
|
| focal |
Released
(1.167.2)
|
|
| groovy |
Released
(1.167.2)
|
|
| upstream |
Needs triage
|
|
| trusty |
Needed
|
|
| jammy |
Not vulnerable
(1.180)
|
|
| kinetic |
Not vulnerable
(1.185)
|
|
| lunar |
Not vulnerable
(1.192)
|
|
| xenial |
Pending
(1.164)
|
|
| impish |
Released
(1.169)
|
|
|
grub2-unsigned Launchpad, Ubuntu, Debian |
hirsute |
Released
(2.04-1ubuntu42)
|
| xenial |
Pending
(2.04-1ubuntu42)
|
|
| bionic |
Released
(2.04-1ubuntu44.1.2)
|
|
| focal |
Released
(2.04-1ubuntu44.2)
|
|
| groovy |
Released
(2.04-1ubuntu44.2)
|
|
| upstream |
Needs triage
|
|
| trusty |
Does not exist
|
|
| jammy |
Not vulnerable
(2.06-2ubuntu7)
|
|
| kinetic |
Not vulnerable
(2.06-2ubuntu12)
|
|
| lunar |
Not vulnerable
(2.06-2ubuntu16)
|
|
| impish |
Released
(2.04-1ubuntu45)
|
|
|
grub2 Launchpad, Ubuntu, Debian |
trusty |
Needed
|
| xenial |
Needed
|
|
| bionic |
Needed
|
|
| focal |
Needed
|
|
| jammy |
Not vulnerable
(2.06-2ubuntu7)
|
|
| kinetic |
Not vulnerable
(2.06-2ubuntu12)
|
|
| lunar |
Not vulnerable
(2.06-2ubuntu16)
|
|
| upstream |
Needs triage
|
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 |