CVE-2020-15707
Published: 29 July 2020
Integer overflows were discovered in the functions grub_cmd_initrd and grub_initrd_init in the efilinux component of GRUB2, as shipped in Debian, Red Hat, and Ubuntu (the functionality is not included in GRUB2 upstream), leading to a heap-based buffer overflow. These could be triggered by an extremely large number of arguments to the initrd command on 32-bit architectures, or a crafted filesystem with very large files on any architecture. An attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. This issue affects GRUB2 version 2.04 and prior versions.
From the Ubuntu Security Team
Colin Watson and Chris Coulson discovered that an integer overflow existed in GRUB2 when handling the initrd command, leading to a heap-based buffer overflow. A local attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions.
Notes
| Author | Note |
|---|---|
| sbeattie | efilinux: Fix integer overflows in grub_cmd_initrd e961f8f8cdb25245900dc0884047e856346035b3 Title: grub2: integer overflows in efilinux grub_cmd_initrd and grub_initrd_init leads to heap based buffer overflow code is not upstream in grub2 but carried as part of patches by Ubuntu, Debian, Red Hat and possibly others. |
| 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 |
jammy |
Not vulnerable
(2.06-2ubuntu7)
|
| kinetic |
Not vulnerable
(2.06-2ubuntu12)
|
|
| lunar |
Not vulnerable
(2.06-2ubuntu16)
|
|
| hirsute |
Not vulnerable
(2.04-1ubuntu26.1)
|
|
| bionic |
Released
(2.02-2ubuntu8.16)
|
|
| focal |
Released
(2.04-1ubuntu26.1)
|
|
| groovy |
Not vulnerable
(2.04-1ubuntu26.1)
|
|
| trusty |
Released
(2.02~beta2-9ubuntu1.20)
Available with Ubuntu Pro or Ubuntu Pro (Infra-only) |
|
| upstream |
Needs triage
|
|
| xenial |
Released
(2.02~beta2-36ubuntu3.26)
|
|
|
grub2-signed Launchpad, Ubuntu, Debian |
jammy |
Not vulnerable
(1.180)
|
| kinetic |
Not vulnerable
(1.185)
|
|
| lunar |
Not vulnerable
(1.192)
|
|
| hirsute |
Not vulnerable
(1.147)
|
|
| bionic |
Released
(1.93.18)
|
|
| focal |
Released
(1.142.3)
|
|
| groovy |
Not vulnerable
(1.147)
|
|
| trusty |
Released
(1.34.22)
Available with Ubuntu Pro or Ubuntu Pro (Infra-only) |
|
| upstream |
Needs triage
|
|
| xenial |
Released
(1.66.26)
|
|
|
grub2-unsigned Launchpad, Ubuntu, Debian |
trusty |
Does not exist
|
| xenial |
Needed
|
|
| bionic |
Not vulnerable
(2.04-1ubuntu47.4)
|
|
| focal |
Not vulnerable
(2.04-1ubuntu47.4)
|
|
| jammy |
Not vulnerable
(2.06-2ubuntu10)
|
|
| kinetic |
Not vulnerable
(2.06-2ubuntu12)
|
|
| lunar |
Not vulnerable
(2.06-2ubuntu16)
|
|
| upstream |
Needs triage
|
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-2020-15707
- 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