kernel: execution in the early microcode loader
Published May 27, 2015
6.9
MEDIUMCVSS 2.0
EPSS 0.42%
Description
Stack-based buffer overflow in the get_matching_model_microcode function in arch/x86/kernel/cpu/microcode/intel_early.c in the Linux kernel before 4.0 allows context-dependent attackers to gain privileges by constructing a crafted microcode header and leveraging root privileges for write access to the initrd.
Affected products
No data.
Configuration 1
- ≥ 3.9 · < 3.10.83
- ≥ 3.11 · < 3.12.40
- ≥ 3.13 · < 3.14.47
- ≥ 3.15 · < 3.16.35
- ≥ 3.17 · < 3.18.19
Configuration 2
- 21
No data.
Red Hat Enterprise Linux 7
kernel-0:3.10.0-229.11.1.ael7b
Fixed · RHSA-2015:1534
Red Hat Enterprise Linux 7
kernel-rt-0:3.10.0-229.11.1.rt56.141.11.el7_1
Fixed · RHSA-2015:1565
Red Hat Enterprise Linux 5
kernel
Not affected
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise MRG 2
kernel-rt
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | kernel-0:3.10.0-229.11.1.ael7b | Fixed | RHSA-2015:1534 |
| Red Hat Enterprise Linux 7 | kernel-rt-0:3.10.0-229.11.1.rt56.141.11.el7_1 | Fixed | RHSA-2015:1565 |
| Red Hat Enterprise Linux 5 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise MRG 2 | kernel-rt | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6 and Red Hat Enteprise MRG 2. Future kernel and kernel-rt updates for Red Hat Enterprise Linux 7 may address this issue.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
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.
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
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.42% (0.00420) | 33.95th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.42% (0.00420) | 33.30th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.10% (0.00103) | 25.94th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.07% (0.00069) | 32.26th | v3 (v2023.03.01) |
| Jun 13, 2024 | 0.07% (0.00069) | 30.15th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.07% (0.00069) | 28.11th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.03% (0.01034) | 41.69th | v2 (v2022.01.01) |
| Sep 10, 2022 | 1.03% (0.01034) | 39.91th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.03% (0.01034) | 37.91th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.03% (0.01034) | 20.32th | v2 (v2022.01.01) |
References (10)
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=f84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4 x_refsource_CONFIRMBroken Link
- http://lists.fedoraproject.org/pipermail/package-announce/2015-March/153329.html vendor-advisoryx_refsource_FEDORAThird Party Advisory
- http://rhn.redhat.com/errata/RHSA-2015-1534.html vendor-advisoryx_refsource_REDHATThird Party Advisory
- http://www.openwall.com/lists/oss-security/2015/03/20/18 mailing-listx_refsource_MLISTMailing List
- http://www.securitytracker.com/id/1032414 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2015-2666 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1204722 x_refsource_CONFIRMIssue Tracking
- https://github.com/torvalds/linux/commit/f84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4 x_refsource_CONFIRMPatch
- https://nvd.nist.gov/vuln/detail/CVE-2015-2666
- https://www.cve.org/CVERecord?id=CVE-2015-2666
| Link | Providers | Tags |
|---|---|---|
| http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=f84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4 | x_refsource_CONFIRMBroken Link | |
| http://lists.fedoraproject.org/pipermail/package-announce/2015-March/153329.html | vendor-advisoryx_refsource_FEDORAThird Party Advisory | |
| http://rhn.redhat.com/errata/RHSA-2015-1534.html | vendor-advisoryx_refsource_REDHATThird Party Advisory | |
| http://www.openwall.com/lists/oss-security/2015/03/20/18 | mailing-listx_refsource_MLISTMailing List | |
| http://www.securitytracker.com/id/1032414 | vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry | |
| https://access.redhat.com/security/cve/CVE-2015-2666 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1204722 | x_refsource_CONFIRMIssue Tracking | |
| https://github.com/torvalds/linux/commit/f84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4 | x_refsource_CONFIRMPatch | |
| https://nvd.nist.gov/vuln/detail/CVE-2015-2666 | ||
| https://www.cve.org/CVERecord?id=CVE-2015-2666 |
Change history (0)
No recorded changes yet.