Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Ubuntu | grub2 in Ubuntu | 20.04 LTS – < 2.04-1ubuntu26.1, 18.04 LTS – < 2.02-2ubuntu8.16, 16.04 LTS – < 2.02~beta2-36ubuntu3.26, 14.04 ESM – < 2.02~beta2-9ubuntu1.20 | 2.04-1ubuntu26.1 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | grub2 | 2.04-9 | — |
| Debian 13 | grub2 | 2.04-9 | — |
| Debian 12 | grub2 | 2.04-9 | — |
| Debian 10 | grub2 | 2.02+dfsg1-20+deb10u1 | DSA-4735-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | grub2 | 2.04-1ubuntu26.1 | USN-4432-1 |
| Ubuntu 20.04 LTS | grub2-signed | 1.142.3 | USN-4432-1 |
| Ubuntu 18.04 LTS | grub2 | 2.02-2ubuntu8.16 | USN-4432-1 |
| Ubuntu 18.04 LTS | grub2-signed | 1.93.18 | USN-4432-1 |
| Ubuntu 16.04 LTS | grub2 | 2.02~beta2-36ubuntu3.26 | USN-4432-1 |
| Ubuntu 16.04 LTS | grub2-signed | 1.66.26 | USN-4432-1 |
| Ubuntu 16.04 LTS | grub2-unsigned | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | grub2 | 2.02~beta2-9ubuntu1.20 | USN-4432-1 |
| Ubuntu Pro 14.04 LTS | grub2-signed | 1.34.22 | USN-4432-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | fwupd | 1.1.4-7.el8_2 | RHSA-2020:3216 |
| RHEL 8 | grub2 +18 | 1:2.02-87.el8_2 | RHSA-2020:3216 |
| RHEL 8 | shim +3 | 15-14.el8_2 | RHSA-2020:3216 |
| RHEL 8 | shim-unsigned-x64 | 15-7.el8 | RHSA-2020:3216 |
| RHEL 7 | fwupdate +3 | 12-6.el7_8 | RHSA-2020:3217 |
| RHEL 7 | grub2 +18 | 1:2.02-0.86.el7_8 | RHSA-2020:3217 |
| RHEL 7 | mokutil +3 | 15-7.el7_8 | RHSA-2020:3217 |
| RHEL 7 | shim +2 | 15-7.el7_9 | RHSA-2020:3217 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.1 EUS | fwupd | 1.1.4-2.el8_1 | RHSA-2020:3223 |
| RHEL 8.1 EUS | grub2 +18 | 1:2.02-87.el8_1 | RHSA-2020:3223 |
| RHEL 8.1 EUS | shim +3 | 15-14.el8_1 | RHSA-2020:3223 |
| RHEL 8.1 EUS | shim-unsigned-x64 | 15-7.el8 | RHSA-2020:3223 |
| RHEL 8.0 E4S | fwupd | 1.1.4-2.el8_0 | RHSA-2020:3227 |
| RHEL 8.0 E4S | grub2 +16 | 1:2.02-87.el8_0 | RHSA-2020:3227 |
| RHEL 8.0 E4S | shim +2 | 15-14.el8_0 | RHSA-2020:3227 |
| RHEL 7.7 EUS | fwupdate +3 | 12-6.el7_7 | RHSA-2020:3274 |
| RHEL 7.7 EUS | grub2 +18 | 1:2.02-0.86.el7_7 | RHSA-2020:3274 |
| RHEL 7.7 EUS | mokutil +3 | 15-8.el7_7 | RHSA-2020:3274 |
| RHEL 7.7 EUS | shim +2 | 15-8.el7 | RHSA-2020:3274 |
| RHEL 7.6 EUS | fwupdate +3 | 12-6.el7_6 | RHSA-2020:3271 |
| RHEL 7.6 EUS | grub2 +18 | 1:2.02-0.86.el7_6 | RHSA-2020:3271 |
| RHEL 7.6 EUS | mokutil +3 | 15-8.el7_6 | RHSA-2020:3271 |
| RHEL 7.6 EUS | shim +2 | 15-8.el7 | RHSA-2020:3271 |
| RHEL 7.4 TUS | fwupdate +3 | 9-10.el7_4 | RHSA-2020:3275 |
| RHEL 7.4 TUS | grub2 +16 | 1:2.02-0.86.el7_4 | RHSA-2020:3275 |
| RHEL 7.4 TUS | mokutil +3 | 15-8.el7_4 | RHSA-2020:3275 |
| RHEL 7.4 TUS | shim +2 | 15-8.el7 | RHSA-2020:3275 |
| RHEL 7.4 E4S | fwupdate +3 | 9-10.el7_4 | RHSA-2020:3275 |
| RHEL 7.4 E4S | grub2 +17 | 1:2.02-0.86.el7_4 | RHSA-2020:3275 |
| RHEL 7.4 E4S | mokutil +3 | 15-8.el7_4 | RHSA-2020:3275 |
| RHEL 7.4 E4S | shim +2 | 15-8.el7 | RHSA-2020:3275 |
| RHEL 7.4 AUS | fwupdate +3 | 9-10.el7_4 | RHSA-2020:3275 |
| RHEL 7.4 AUS | grub2 +16 | 1:2.02-0.86.el7_4 | RHSA-2020:3275 |
| RHEL 7.4 AUS | mokutil +3 | 15-8.el7_4 | RHSA-2020:3275 |
| RHEL 7.4 AUS | shim +2 | 15-8.el7 | RHSA-2020:3275 |
| RHEL 7.3 TUS | grub2 +16 | 1:2.02-0.86.el7 | RHSA-2020:3276 |
| RHEL 7.3 TUS | mokutil +1 | 15-8.el7_3 | RHSA-2020:3276 |
| RHEL 7.3 TUS | shim +2 | 15-8.el7 | RHSA-2020:3276 |
| RHEL 7.3 E4S | grub2 +17 | 1:2.02-0.86.el7 | RHSA-2020:3276 |
| RHEL 7.3 E4S | mokutil +1 | 15-8.el7_3 | RHSA-2020:3276 |
| RHEL 7.3 E4S | shim +2 | 15-8.el7 | RHSA-2020:3276 |
| RHEL 7.3 AUS | grub2 +16 | 1:2.02-0.86.el7 | RHSA-2020:3276 |
| RHEL 7.3 AUS | mokutil +1 | 15-8.el7_3 | RHSA-2020:3276 |
| RHEL 7.3 AUS | shim +2 | 15-8.el7 | RHSA-2020:3276 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | grub2 | 2.04-9.7.1 | SUSE-SU-2020:2074-1 |
| SLES 15 SP1 | grub2 | 2.02-26.25.1 | SUSE-SU-2020:2077-1 |
| SLES 15 | grub2 | 2.02-19.48.1 | SUSE-SU-2020:2073-1 |
| SLES 12 SP5 | grub2 | 2.02-12.31.1 | SUSE-SU-2020:2078-1 |
| SLES 12 SP4 | grub2 | 2.02-12.31.1 | SUSE-SU-2020:2078-1 |
Show 16 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | grub2 | 2.02-4.53.1 | SUSE-SU-2020:2079-1 |
| SLES 12 SP2 | grub2 | 2.02~beta2-115.49.1 | SUSE-SU-2020:2076-1 |
| SLES 11 SP4 | grub2 | 2.00-0.66.15.1 | SUSE-SU-2020:14440-1 |
| SLES for SAP 15 | grub2 | 2.02-19.48.1 | SUSE-SU-2020:2073-1 |
| SLES for SAP 12 SP5 | grub2 | 2.02-12.31.1 | SUSE-SU-2020:2078-1 |
| SLES for SAP 12 SP4 | grub2 | 2.02-12.31.1 | SUSE-SU-2020:2078-1 |
| SLES for SAP 12 SP3 | grub2 | 2.02-4.53.1 | SUSE-SU-2020:2079-1 |
| SLES for SAP 12 SP2 | grub2 | 2.02~beta2-115.49.1 | SUSE-SU-2020:2076-1 |
| SLE HPC 15 | grub2 | 2.02-19.48.1 | SUSE-SU-2020:2073-1 |
| SUSE OpenStack Cloud Crowbar 9 | grub2 | 2.02-12.31.1 | SUSE-SU-2020:2078-1 |
| SUSE OpenStack Cloud Crowbar 8 | grub2 | 2.02-4.53.1 | SUSE-SU-2020:2079-1 |
| SUSE OpenStack Cloud 9 | grub2 | 2.02-12.31.1 | SUSE-SU-2020:2078-1 |
| SUSE OpenStack Cloud 8 | grub2 | 2.02-4.53.1 | SUSE-SU-2020:2079-1 |
| SUSE OpenStack Cloud 7 | grub2 | 2.02~beta2-115.49.1 | SUSE-SU-2020:2076-1 |
| SUSE HPE Helion OpenStack 8 | grub2 | 2.02-4.53.1 | SUSE-SU-2020:2079-1 |
| SUSE Enterprise Storage 5 | grub2 | 2.02-4.53.1 | SUSE-SU-2020:2079-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | grub2 | 2.06-7.1 | openSUSE-SU-2024:10824-1 |
| openSUSE Leap 15.2 | grub2 | 2.04-lp152.7.3.4 | openSUSE-SU-2020:1169-1 |
| openSUSE Leap 15.1 | grub2 | 2.02-lp151.21.21.4 | openSUSE-SU-2020:1168-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | grub | 2.06-r0 | — |
| Alpine v3.23 | grub | 2.06-r0 | — |
| Alpine v3.22 | grub | 2.06-r0 | — |
| Alpine v3.21 | grub | 2.06-r0 | — |
| Alpine v3.20 | grub | 2.06-r0 | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | grub | 2.06-r0 | — |
| Alpine v3.18 | grub | 2.06-r0 | — |
| Alpine v3.17 | grub | 2.06-r0 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | grub2-pc +15 | 1:2.02-82.0.2.el8_2.1 | ELSA-2020-5786 |
| Oracle Linux 7 | grub2 +12 | 1:2.02-0.81.0.3.el7 | ELSA-2020-5790, ELSA-2020-5782 |
| Oracle Linux 7 | grub2-efi-aa64 +1 | 1:2.02-0.81.0.4.el7 | ELSA-2020-5790 |
Advisories 25
- USN-4432-1 grub2, grub2-signed vulnerabilities Ubuntu Security Notices (USN) · Jun 29, 2026
- RHSA-2020:3276 Red Hat Security Advisory: grub2 security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2020:3274 Red Hat Security Advisory: grub2 security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2020:3275 Red Hat Security Advisory: grub2 security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2020:3271 Red Hat Security Advisory: grub2 security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2020:3227 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2020:3223 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2020:3217 Red Hat Security Advisory: grub2 security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2020:3216 Red Hat Security Advisory: grub2 security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- WID-SEC-2022-0553 Grub2: Mehrere Schwachstellen ermöglichen Umgehen von Sicherheitsvorkehrungen BSI CERT-Bund (WID) · Mar 17, 2026
- DSA-4735-1 grub2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2020:2079-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2076-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1168-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2077-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2078-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1169-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:14440-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10824-1 grub2-2.06-7.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2074-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2073-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- ICSA-21-336-06 Hitachi Energy APM Edge CISA ICS & IT advisories · Dec 2, 2021
- ELSA-2020-5782 Important: grub2 security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jul 29, 2020
- ELSA-2020-5790 Important: grub2 security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jul 29, 2020
- ELSA-2020-5786 Important: grub2 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jul 29, 2020
References
- https://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/
- https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypass vendor-advisory
- http://ubuntu.com/security/notices/USN-4432-1 vendor-advisory
- https://www.debian.org/security/2020-GRUB-UEFI-SecureBoot vendor-advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200011
- https://access.redhat.com/security/vulnerabilities/grub2bootloader vendor-advisory
- https://www.suse.com/c/suse-addresses-grub2-secure-boot-issue/ vendor-advisory
- https://www.suse.com/support/kb/doc/?id=000019673 vendor-advisory
- https://www.openwall.com/lists/oss-security/2020/07/29/3
- https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html
- DSA-4735 vendor-advisory
- [oss-security] 20200729 multiple secure boot grub2 and linux kernel vulnerabilities mailing-list
- https://security.netapp.com/advisory/ntap-20200731-0008/
- USN-4432-1 vendor-advisory
- openSUSE-SU-2020:1169 vendor-advisory
- openSUSE-SU-2020:1168 vendor-advisory
- GLSA-202104-05 vendor-advisory