xen: x86: race condition in Xen mapping code (XSA-345)
Published Oct 22, 2020
7.8
HIGHCVSS 3.1
EPSS 0.26%
Description
An issue was discovered in Xen through 4.14.x allowing x86 guest OS users to cause a host OS denial of service, achieve data corruption, or possibly gain privileges by exploiting a race condition that leads to a use-after-free involving 2MiB and 1GiB superpages.
Affected products
No data.
Configuration 2
- 31
Configuration 4
- 10.0
No data.
Red Hat Enterprise Linux 5
kernel-xen
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | kernel-xen | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
All Xen versions from 3.2 onwards are vulnerable. Red Hat Enterprise Linux 5 is not affected by this flaw, as it shipped with an older version of Xen.
Red Hat mitigation
Running all guests in HVM or PVH mode, in each case with HAP enabled, will prevent those guests from exploiting the vulnerability.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
1 other source (Red Hat) ▾
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/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.
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 (14 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.26% (0.00264) | 16.46th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.26% (0.00260) | 17.15th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.07% (0.00065) | 17.31th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.04% (0.00045) | 16.02th | v3 (v2023.03.01) |
| Jun 10, 2024 | 0.04% (0.00045) | 14.07th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.04% (0.00045) | 12.06th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.10% (0.01104) | 54.09th | v2 (v2022.01.01) |
| Sep 17, 2022 | 1.10% (0.01104) | 52.45th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.10% (0.01104) | 50.41th | v2 (v2022.01.01) |
| Feb 4, 2022 | 4.41% (0.04411) | 70.76th | v2 (v2022.01.01) |
| Feb 3, 2022 | 9.61% (0.09608) | 87.22th | v1 |
| Jan 6, 2022 | 9.61% (0.09608) | 87.07th | v1 |
| Sep 1, 2021 | 2.31% (0.02314) | 78.25th | v1 |
| Apr 14, 2021 | 2.31% (0.02314) | 0.00th | v1 |
References (12)
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00075.html vendor-advisoryx_refsource_SUSEMailing ListThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00025.html vendor-advisoryx_refsource_SUSEMailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/01/19/7 mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- http://xenbits.xen.org/xsa/advisory-345.html x_refsource_CONFIRMPatchVendor Advisory
- https://access.redhat.com/security/cve/CVE-2020-27672 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1891096 Issue Tracking
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XIK57QJOVOPWH6RFRNMGOBCROBCKMDG2/ vendor-advisoryx_refsource_FEDORA
- https://nvd.nist.gov/vuln/detail/CVE-2020-27672
- https://security.gentoo.org/glsa/202011-06 vendor-advisoryx_refsource_GENTOOThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2020-27672
- https://www.debian.org/security/2020/dsa-4804 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://xenbits.xen.org/xsa/advisory-345.html x_refsource_MISCPatchVendor Advisory
Change history (0)
No recorded changes yet.