kernel: Double-fetch vulnerability in drivers/virt/vboxguest/vboxguest_linux.c:vbg_misc_device_ioctl() allows information leak and local denial of service
Published Jun 22, 2018
6.3
MEDIUMCVSS 3.0
EPSS 0.26%
Description
An issue was discovered in the Linux kernel through 4.17.2. vbg_misc_device_ioctl() in drivers/virt/vboxguest/vboxguest_linux.c reads the same user data twice with copy_from_user. The header part of the user data is double-fetched, and a malicious user thread can tamper with the critical variables (hdr.size_in and hdr.size_out) in the header between the two fetches because of a race condition, leading to severe kernel errors, such as buffer over-accesses. This bug can cause a local denial of service and information leakage.
Affected products
No data.
- ≤ 4.17.2
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:H/PR:L/UI:N/S:U/C:H/I:N/A:H
1 other source (Red Hat) ▾
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H
AV:L/AC:M/Au:N/C:C/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 v5
- EPSS v2
- EPSS v3
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
Table of values (8 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.26% (0.00264) | 16.62th | v5 (v2026.06.15) |
| Sep 20, 2026 | 0.26% (0.00264) | 18.67th | v5 (v2026.06.15) |
| Jul 20, 2024 | 0.04% (0.00042) | 5.06th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.04% (0.00042) | 5.63th | v3 (v2023.03.01) |
| Mar 6, 2023 | 0.89% (0.00890) | 30.33th | v2 (v2022.01.01) |
| Feb 4, 2022 | 0.89% (0.00890) | 12.04th | v2 (v2022.01.01) |
| Feb 3, 2022 | 0.55% (0.00553) | 12.78th | v5 (v2026.06.15) |
| Apr 14, 2021 | 0.55% (0.00553) | 0.00th | v1 |
References (7)
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bd23a7269834dc7c1f93e83535d16ebc44b75eba x_refsource_MISCPatchVendor Advisory
- https://access.redhat.com/security/cve/CVE-2018-12633 Vendor Advisory
- https://bugzilla.kernel.org/show_bug.cgi?id=200131 x_refsource_MISCIssue TrackingVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1594170 Issue Tracking
- https://github.com/torvalds/linux/commit/bd23a7269834dc7c1f93e83535d16ebc44b75eba x_refsource_MISCPatchThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2018-12633
- https://www.cve.org/CVERecord?id=CVE-2018-12633
| Link | Providers | Tags |
|---|---|---|
| http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bd23a7269834dc7c1f93e83535d16ebc44b75eba | x_refsource_MISCPatchVendor Advisory | |
| https://access.redhat.com/security/cve/CVE-2018-12633 | Vendor Advisory | |
| https://bugzilla.kernel.org/show_bug.cgi?id=200131 | x_refsource_MISCIssue TrackingVendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1594170 | Issue Tracking | |
| https://github.com/torvalds/linux/commit/bd23a7269834dc7c1f93e83535d16ebc44b75eba | x_refsource_MISCPatchThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2018-12633 | ||
| https://www.cve.org/CVERecord?id=CVE-2018-12633 |
Change history (0)
No recorded changes yet.