kernel: kvm: insufficient sysenter emulation when invoked from 16-bit code
Published Mar 2, 2015
4.4
MEDIUMCVSS 2.0
EPSS 0.64%
Description
The em_sysenter function in arch/x86/kvm/emulate.c in the Linux kernel before 3.18.5, when the guest OS lacks SYSENTER MSR initialization, allows guest OS users to gain guest OS privileges or cause a denial of service (guest OS crash) by triggering use of a 16-bit code segment for emulation of a SYSENTER instruction.
Affected products
No data.
Configuration 1
- < 3.18.5
Configuration 2
- 12.04
- 14.04
- 14.10
Configuration 3
- 7.0
- 8.0
Configuration 5
- 6.0
- 6.0
- 6.0
No data.
Red Hat Enterprise Linux 6
kernel-0:2.6.32-573.el6
Fixed · RHSA-2015:1272
Red Hat Enterprise Linux 7
kernel-0:3.10.0-327.el7
Fixed · RHSA-2015:2152
Red Hat Enterprise Linux 5
kvm
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise MRG 2
realtime-kernel
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | kernel-0:2.6.32-573.el6 | Fixed | RHSA-2015:1272 |
| Red Hat Enterprise Linux 7 | kernel-0:3.10.0-327.el7 | Fixed | RHSA-2015:2152 |
| Red Hat Enterprise Linux 5 | kvm | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise MRG 2 | realtime-kernel | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue did not affect the kvm packages as shipped with Red Hat Enterprise Linux 5 as they lack support for sysenter instruction emulation. This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 7. A future update may address this issue. Please note that the Red Hat Enterprise Linux with KVM certified guest operating systems do initialize the SYSENTER MSRs and are thus not vulnerable to this issue when running on KVM hypervisor.
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:P/I:P/A:P
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 (11 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.64% (0.00643) | 48.92th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.64% (0.00643) | 45.81th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.11% (0.00110) | 26.93th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.14% (0.00144) | 51.74th | v3 (v2023.03.01) |
| Jun 2, 2023 | 0.15% (0.00153) | 50.32th | v3 (v2023.03.01) |
| Apr 30, 2023 | 0.14% (0.00142) | 48.63th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.11% (0.00115) | 43.55th | 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 (21)
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=f3747379accba8e95d70cec0eae0582c8c182050 x_refsource_CONFIRM
- http://permalink.gmane.org/gmane.linux.kernel.commits.head/502245 mailing-listx_refsource_MLISTBroken Link
- http://rhn.redhat.com/errata/RHSA-2015-1272.html vendor-advisoryx_refsource_REDHATThird Party Advisory
- http://www.debian.org/security/2015/dsa-3170 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.18.5 x_refsource_CONFIRMRelease NotesVendor Advisory
- http://www.mandriva.com/security/advisories?name=MDVSA-2015:058 vendor-advisoryx_refsource_MANDRIVAThird Party Advisory
- http://www.openwall.com/lists/oss-security/2015/01/27/6 mailing-listx_refsource_MLISTExploitMailing ListThird Party Advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html x_refsource_CONFIRMThird Party Advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html x_refsource_CONFIRMThird Party Advisory
- http://www.securityfocus.com/bid/72842 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.ubuntu.com/usn/USN-2513-1 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- http://www.ubuntu.com/usn/USN-2514-1 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- http://www.ubuntu.com/usn/USN-2515-1 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- http://www.ubuntu.com/usn/USN-2516-1 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- http://www.ubuntu.com/usn/USN-2517-1 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- http://www.ubuntu.com/usn/USN-2518-1 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2015-0239 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1186448 x_refsource_CONFIRMIssue TrackingThird Party Advisory
- https://github.com/torvalds/linux/commit/f3747379accba8e95d70cec0eae0582c8c182050 x_refsource_CONFIRMPatchThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2015-0239
- https://www.cve.org/CVERecord?id=CVE-2015-0239
Change history (0)
No recorded changes yet.