grub2: buffer overflow when checking password entered during bootup
Published Dec 16, 2015
7.4
HIGHCVSS 3.1
EPSS 1.09%
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.
Affected products
No data.
No data.
Red Hat Enterprise Linux 7
grub2-1:2.02-0.33.el7_2
Fixed · RHSA-2015:2623
Red Hat Enterprise Linux 5
grub
Not affected
Red Hat Enterprise Linux 6
grub
Not affected
Red Hat Enterprise Linux 8
grub2
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | grub2-1:2.02-0.33.el7_2 | Fixed | RHSA-2015:2623 |
| Red Hat Enterprise Linux 5 | grub | Not affected | n/a |
| Red Hat Enterprise Linux 6 | grub | Not affected | n/a |
| Red Hat Enterprise Linux 8 | grub2 | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
AV:L/AC:M/Au:N/C:C/I:C/A:C
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
PoCAutomatable
NoTechnical Impact
TotalDecision
n/aAssessed Mar 6, 2024 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (15 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.09% (0.01095) | 64.31th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.10% (0.01104) | 61.36th | v5 (v2026.06.15) |
| Apr 1, 2026 | 5.05% (0.05055) | 89.73th | v4 (v2025.03.14) |
| Feb 26, 2026 | 3.05% (0.03054) | 86.46th | v4 (v2025.03.14) |
| Feb 20, 2026 | 5.05% (0.05055) | 89.56th | v4 (v2025.03.14) |
| Mar 30, 2025 | 2.77% (0.02766) | 84.75th | v4 (v2025.03.14) |
| Mar 29, 2025 | 12.68% (0.12683) | 89.95th | v4 (v2025.03.14) |
| Mar 17, 2025 | 2.77% (0.02766) | 85.07th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.11% (0.00108) | 45.35th | v3 (v2023.03.01) |
| Jun 26, 2024 | 0.11% (0.00108) | 43.99th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.11% (0.00108) | 41.98th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.55% (0.01547) | 74.98th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.55% (0.01547) | 74.94th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.55% (0.01547) | 72.92th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.55% (0.01547) | 51.82th | v2 (v2022.01.01) |
References (27)
- http://hmarco.org/bugs/CVE-2015-8370-Grub2-authentication-bypass.html Exploit
- http://lists.fedoraproject.org/pipermail/package-announce/2015-December/173703.html vendor-advisory
- http://lists.fedoraproject.org/pipermail/package-announce/2015-December/174049.html vendor-advisory
- http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00037.html vendor-advisory
- http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00039.html vendor-advisory
- http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00040.html vendor-advisory
- http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00041.html vendor-advisory
- http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00043.html vendor-advisory
- http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00044.html vendor-advisory
- http://lists.opensuse.org/opensuse-security-announce/2016-01/msg00003.html vendor-advisory
- http://packetstormsecurity.com/files/134831/Grub2-Authentication-Bypass.html
- http://rhn.redhat.com/errata/RHSA-2015-2623.html vendor-advisory
- http://seclists.org/fulldisclosure/2015/Dec/69 mailing-list
- http://www.debian.org/security/2015/dsa-3421 vendor-advisory
- http://www.openwall.com/lists/oss-security/2015/12/15/6 mailing-list
- http://www.openwall.com/lists/oss-security/2024/01/15/3 mailing-list
- http://www.oracle.com/technetwork/topics/security/cpujan2016-2367955.html Patch
- http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
- http://www.securityfocus.com/archive/1/537115/100/0/threaded mailing-list
- http://www.securityfocus.com/bid/79358 vdb-entry
- http://www.securitytracker.com/id/1034422 vdb-entry
- http://www.ubuntu.com/usn/USN-2836-1 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2015-8370 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1286966 Issue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2015-8370
- https://security.gentoo.org/glsa/201512-03 vendor-advisory
- https://www.cve.org/CVERecord?id=CVE-2015-8370
Change history (0)
No recorded changes yet.