kernel: Out of bounds read in ext4/balloc.c:ext4_valid_block_bitmap() causes crash with crafted ext4 image
Published Apr 2, 2018
5.5
MEDIUMCVSS 3.0
EPSS 1.92%
Description
The ext4_valid_block_bitmap function in fs/ext4/balloc.c in the Linux kernel through 4.15.15 allows attackers to cause a denial of service (out-of-bounds read and system crash) via a crafted ext4 image because balloc.c and ialloc.c do not validate bitmap block numbers.
Affected products
- Vendor n/a Product Linux kernel through version 4.15 Defaultn/a
- Version Linux kernel through version 4.15StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n/a | Linux kernel through version 4.15 | n/a |
|
- ≤ 4.15.15
No data.
Red Hat Enterprise Linux 5
kernel
Not affected
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-alt
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Not affected
Red Hat Enterprise MRG 2
realtime-kernel
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-alt | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Not affected | n/a |
| Red Hat Enterprise MRG 2 | realtime-kernel | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
1 other source (Red Hat) ▾
CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AV:N/AC:M/Au:N/C:N/I:N/A:C
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (23 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.92% (0.01922) | 79.18th | v5 (v2026.06.15) |
| Sep 22, 2026 | 1.92% (0.01922) | 79.03th | v5 (v2026.06.15) |
| Sep 21, 2026 | 4.00% (0.04000) | 90.11th | v5 (v2026.06.15) |
| Sep 20, 2026 | 1.92% (0.01922) | 79.01th | v5 (v2026.06.15) |
| Sep 6, 2026 | 1.97% (0.01968) | 79.07th | v5 (v2026.06.15) |
| Sep 5, 2026 | 4.04% (0.04045) | 89.98th | v5 (v2026.06.15) |
| Aug 30, 2026 | 1.97% (0.01968) | 78.97th | v5 (v2026.06.15) |
| Aug 28, 2026 | 4.04% (0.04045) | 89.92th | v5 (v2026.06.15) |
| Aug 24, 2026 | 1.97% (0.01968) | 78.85th | v5 (v2026.06.15) |
| Aug 23, 2026 | 4.04% (0.04045) | 89.88th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.00% (0.01999) | 78.08th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.18% (0.00176) | 36.79th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.23% (0.00232) | 62.17th | v3 (v2023.03.01) |
| Jul 10, 2024 | 0.23% (0.00232) | 61.63th | v3 (v2023.03.01) |
| Mar 26, 2023 | 0.23% (0.00232) | 59.60th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.17% (0.00166) | 51.53th | v3 (v2023.03.01) |
| Mar 6, 2023 | 2.69% (0.02686) | 82.85th | v2 (v2022.01.01) |
| Apr 1, 2022 | 2.69% (0.02686) | 81.17th | v2 (v2022.01.01) |
| Feb 4, 2022 | 2.69% (0.02686) | 62.66th | v2 (v2022.01.01) |
| Feb 3, 2022 | 3.81% (0.03812) | 72.37th | v1 |
| Jan 6, 2022 | 3.81% (0.03812) | 72.13th | v1 |
| Sep 1, 2021 | 3.81% (0.03812) | 82.91th | v1 |
| Apr 14, 2021 | 3.81% (0.03812) | 0.00th | v1 |
References (17)
- http://openwall.com/lists/oss-security/2018/03/29/1 x_refsource_MISCMailing List
- https://access.redhat.com/security/cve/CVE-2018-1093 Vendor Advisory
- https://bugzilla.kernel.org/show_bug.cgi?id=199181 x_refsource_MISCIssue Tracking
- https://bugzilla.redhat.com/show_bug.cgi?id=1560782 x_refsource_MISCIssue TrackingThird Party Advisory
- https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git/commit/?id=7dac4a1726a9c64a517d595c40e95e2d0d135f6f x_refsource_MISCPatch
- https://lists.debian.org/debian-lts-announce/2018/06/msg00000.html mailing-listx_refsource_MLIST
- https://lists.debian.org/debian-lts-announce/2018/07/msg00015.html mailing-listx_refsource_MLIST
- https://lists.debian.org/debian-lts-announce/2018/07/msg00016.html mailing-listx_refsource_MLIST
- https://nvd.nist.gov/vuln/detail/CVE-2018-1093
- https://usn.ubuntu.com/3676-1/ vendor-advisoryx_refsource_UBUNTU
- https://usn.ubuntu.com/3676-2/ vendor-advisoryx_refsource_UBUNTU
- https://usn.ubuntu.com/3752-1/ vendor-advisoryx_refsource_UBUNTU
- https://usn.ubuntu.com/3752-2/ vendor-advisoryx_refsource_UBUNTU
- https://usn.ubuntu.com/3752-3/ vendor-advisoryx_refsource_UBUNTU
- https://usn.ubuntu.com/3754-1/ vendor-advisoryx_refsource_UBUNTU
- https://www.cve.org/CVERecord?id=CVE-2018-1093
- https://www.debian.org/security/2018/dsa-4188 vendor-advisoryx_refsource_DEBIAN
Change history (0)
No recorded changes yet.