CVE-2020-14311
Published: 29 July 2020
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.
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 |
Priority
Status
Package | Release | Status |
---|---|---|
grub2 Launchpad, Ubuntu, Debian |
bionic |
Released
(2.02-2ubuntu8.16)
|
focal |
Released
(2.04-1ubuntu26.1)
|
|
groovy |
Not vulnerable
(2.04-1ubuntu26.1)
|
|
hirsute |
Not vulnerable
(2.04-1ubuntu26.1)
|
|
precise |
Ignored
(end of ESM support, was needed)
|
|
trusty |
Released
(2.02~beta2-9ubuntu1.20)
|
|
upstream |
Needs triage
|
|
xenial |
Released
(2.02~beta2-36ubuntu3.26)
|
|
grub2-signed Launchpad, Ubuntu, Debian |
bionic |
Released
(1.93.18)
|
eoan |
Ignored
(reached end-of-life)
|
|
focal |
Released
(1.142.3)
|
|
groovy |
Not vulnerable
(1.147)
|
|
hirsute |
Not vulnerable
(1.147)
|
|
precise |
Does not exist
|
|
trusty |
Released
(1.34.22)
|
|
upstream |
Needs triage
|
|
xenial |
Released
(1.66.26)
|
Severity score breakdown
Parameter | Value |
---|---|
Base score | 5.7 |
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 |
References
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-14311
- https://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/
- https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypass
- https://www.openwall.com/lists/oss-security/2020/07/29/3
- https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html
- https://ubuntu.com/security/notices/USN-4432-1
- NVD
- Launchpad
- Debian