CVE-2020-27779
Published: 2 March 2021
A flaw was found in grub2 in versions prior to 2.06. The cutmem command does not honor secure boot locking allowing an privileged attacker to remove address ranges from memory creating an opportunity to circumvent SecureBoot protections after proper triage about grub's memory layout. 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 cutmem command in GRUB 2 did not honor secure boot locking. 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
CVSS 3 base score: 7.5
Status
| Package | Release | Status |
|---|---|---|
|
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 |
Released
(1.169)
|
|
| kinetic |
Released
(1.169)
|
|
| precise |
Does not exist
|
|
| trusty |
Needs triage
|
|
| upstream |
Needs triage
|
|
| xenial |
Pending
(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 |
Released
(2.04-1ubuntu45)
|
|
| kinetic |
Released
(2.04-1ubuntu45)
|
|
| precise |
Ignored
(end of ESM support, was needs-triage)
|
|
| trusty |
Needs triage
|
|
| upstream |
Needs triage
|
|
| xenial |
Pending
(2.04-1ubuntu42)
|