CVE-2020-14311

Publication date 29 July 2020

Last updated 24 July 2024

Ubuntu priority

High

Why this priority?

Cvss 3 Severity Score

5.7 · Medium

Score breakdown

There is an issue with grub2 before version 2.06 while handling symlink on ext filesystems. A filesystem containing a symbolic link with an inode size of UINT32_MAX causes an arithmetic overflow leading to a zero-sized memory allocation with subsequent heap-based buffer overflow.

From the Ubuntu Security Team

Chris Coulson discovered that multiple integer overflows existed in GRUB2 when handling certain filesystems, font files or PNG images, leading to heap-based buffer overflows. A local attacker could use these to execute arbitrary code and bypass UEFI Secure Boot restrictions.

Read the notes from the security team

Status

Package Ubuntu Release Status
grub2 24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.04 hirsute
Not affected
20.10 groovy
Not affected
20.04 LTS focal
Fixed 2.04-1ubuntu26.1
18.04 LTS bionic
Fixed 2.02-2ubuntu8.16
16.04 LTS xenial
Fixed 2.02~beta2-36ubuntu3.26
14.04 LTS trusty
grub2-signed 24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.04 hirsute
Not affected
20.10 groovy
Not affected
20.04 LTS focal
Fixed 1.142.3
19.10 eoan Ignored end of life
18.04 LTS bionic
Fixed 1.93.18
16.04 LTS xenial
Fixed 1.66.26
14.04 LTS trusty
grub2-unsigned 24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Fixed 2.04-1ubuntu47.4
18.04 LTS bionic
Fixed 2.04-1ubuntu47.4
16.04 LTS xenial
Vulnerable
14.04 LTS trusty Not in release

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Notes

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

Severity score breakdown

Parameter Value
Base score 5.7 · Medium
Attack vector Local
Attack complexity High
Privileges required High
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:H