CVE-2020-14309
Publication date 29 July 2020
Last updated 24 July 2024
Ubuntu priority
Cvss 3 Severity Score
There's an issue with grub2 in all versions before 2.06 when handling squashfs filesystems containing a symbolic link with name length of UINT32 bytes in size. The name size leads to an arithmetic overflow leading to a zero-size allocation further causing a heap-based buffer overflow with attacker controlled data.
From the Ubuntu Security Team
Chris Coulson discovered that multiple integer overflows existed in GRUB2 when handling certain filesystems or font files, leading to heap-based buffer overflows. A local attacker could use these to execute arbitrary code and bypass UEFI Secure Boot restrictions.
Status
Package | Ubuntu Release | Status |
---|---|---|
grub2 | 24.10 oracular |
Not affected
|
24.04 LTS noble |
Not affected
|
|
22.04 LTS jammy |
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 |
Fixed 2.02~beta2-9ubuntu1.20
|
|
grub2-signed | 24.10 oracular |
Not affected
|
24.04 LTS noble |
Not affected
|
|
22.04 LTS jammy |
Not affected
|
|
20.04 LTS focal |
Fixed 1.142.3
|
|
18.04 LTS bionic |
Fixed 1.93.18
|
|
16.04 LTS xenial |
Fixed 1.66.26
|
|
14.04 LTS trusty |
Fixed 1.34.22
|
|
grub2-unsigned | 24.10 oracular |
Not affected
|
24.04 LTS noble |
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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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 |
References
Related Ubuntu Security Notices (USN)
- USN-4432-1
- GRUB 2 vulnerabilities
- 29 July 2020
Other references
- https://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/
- https://wiki.sne.bianheman.eu.org/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://www.cve.org/CVERecord?id=CVE-2020-14309