Description
Multiple integer underflows in Grub2 1.98 through 2.02 allow physically proximate attackers to bypass authentication, obtain sensitive information, or cause a denial of service (disk corruption) via backspace characters in the (1) grub_username_get function in grub-core/normal/auth.c or the (2) grub_password_get function in lib/crypto.c, which trigger an "Off-by-two" or "Out of bounds overwrite" memory error.
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 | 2.02~beta2-33 | — |
| Debian 13 | grub2 | 2.02~beta2-33 | — |
| Debian 12 | grub2 | 2.02~beta2-33 | — |
| Debian 8 | grub2 | 2.02~beta2-22+deb8u1 | DSA-3421-1 |
| Debian 7 | grub2 | 1.99-27+deb7u3 | DSA-3421-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 6.0 | grub2 | 1.98+20100804-14+squeeze2 | DLA-368-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | grub2 | 2.02~beta2-9ubuntu1.6 | USN-2836-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | grub2 +3 | 1:2.02-0.33.el7_2 | RHSA-2015:2623 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP1 | grub2 | 2.02~beta2-73.3 | SUSE-SU-2015:2387-1 |
| SLES 12 | grub2 | 2.02~beta2-56.9.4 | SUSE-SU-2015:2399-1 |
| SLES 11 SP4 | grub2 | 2.00-0.54.2 | SUSE-SU-2015:2385-1 |
| SLES 11 SP3 | grub2 | 2.00-0.49.2 | SUSE-SU-2015:2386-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP1 | grub2 | 2.02~beta2-73.3 | SUSE-SU-2015:2387-1 |
| SLES for SAP 12 | grub2 | 2.02~beta2-56.9.4 | SUSE-SU-2015:2399-1 |
| SLES for SAP 11 SP4 | grub2 | 2.00-0.54.2 | SUSE-SU-2015:2385-1 |
| SLES for SAP 11 SP3 | grub2 | 2.00-0.49.2 | SUSE-SU-2015:2386-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | grub2 | 2.02~beta3-15.1 | openSUSE-SU-2024:10078-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | grub2 +3 | 1:2.02-0.33.0.1.el7_2 | ELSA-2015-2623 |
Advisories 10
- RHSA-2015:2623 Red Hat Security Advisory: grub2 security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-3421-1 grub2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-368-1 grub2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-2836-1 grub2 vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2015:2399-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:2386-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:2385-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10078-1 grub2-2.02~beta3-15.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:2387-1 Security update for grub2 SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2015-2623 Moderate: grub2 security and bug fix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Dec 15, 2015
References
- http://packetstormsecurity.com/files/134831/Grub2-Authentication-Bypass.html
- openSUSE-SU-2015:2392 vendor-advisory
- openSUSE-SU-2016:0036 vendor-advisory
- http://hmarco.org/bugs/CVE-2015-8370-Grub2-authentication-bypass.html
- 79358 vdb-entry
- openSUSE-SU-2015:2375 vendor-advisory
- 1034422 vdb-entry
- http://www.oracle.com/technetwork/topics/security/cpujan2016-2367955.html
- SUSE-SU-2015:2387 vendor-advisory
- SUSE-SU-2015:2386 vendor-advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
- [oss-security] 20151215 Back to 28: Grub2 Authentication Bypass 0-Day [CVE-2015-8370] mailing-list
- 20151215 Back to 28: Grub2 Authentication Bypass 0-Day [CVE-2015-8370] mailing-list
- SUSE-SU-2015:2385 vendor-advisory
- 20151216 Back to 28: Grub2 Authentication Bypass 0-Day [CVE-2015-8370] mailing-list
- GLSA-201512-03 vendor-advisory
- FEDORA-2015-cebe5133e7 vendor-advisory
- USN-2836-1 vendor-advisory
- FEDORA-2015-90c27b6e91 vendor-advisory
- RHSA-2015:2623 vendor-advisory
- SUSE-SU-2015:2399 vendor-advisory
- DSA-3421 vendor-advisory
- [oss-security] 20240116 CVE-2023-4001: a password bypass vulnerability in the downstream GRUB boot manager mailing-list