TI-2021-09763 Aliases CVE-2021-28697 GHSA-2h72-2hx7-mmcq

Race condition in xen

LOW 34CWE-362Published 2021-08-27 · Updated 2024-08-03

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

grant table v2 status pages may remain accessible after de-allocation Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes.

Why it matters now

EPSS 0.00263 18th percentileScored 2026-11-07

Fix Fixed xen (Xen): next of 4.14.x, next of 4.12.x

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Xen	xen	xen-unstable	—	No fix listed	CNA
Xen	xen	4.13.x and later	next of 4.14.x	Patch available	CNA
Xen	xen	4.11.x and later	next of 4.12.x	Patch available	CNA
Xen	xen	4.15.x	—	No fix listed	CNA

xen VendorXen Affected xen-unstable Fixed in — No fix listed CNA
xen VendorXen Affected 4.13.x and later Fixed in next of 4.14.x Patch available CNA
xen VendorXen Affected 4.11.x and later Fixed in next of 4.12.x Patch available CNA
xen VendorXen Affected 4.15.x Fixed in — No fix listed CNA

CPE configurations NVD · 5

CPE	Versions	Role	Vendor
cpe:2.3:o:xen:xen::::::::	4.0.0 – 4.15.0	Vulnerable	Xen
cpe:2.3:o:fedoraproject:fedora:33:::::::*	33	Vulnerable	Fedoraproject
cpe:2.3:o:fedoraproject:fedora:34:::::::*	34	Vulnerable	Fedoraproject
cpe:2.3:o:fedoraproject:fedora:35:::::::*	35	Vulnerable	Fedoraproject
cpe:2.3:o:debian:debian_linux:11.0:::::::*	11.0	Vulnerable	Debian

cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:* Versions 4.0.0 – 4.15.0 Vulnerable ·Xen
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* Versions 35 Vulnerable ·Fedoraproject
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian

Remediation

Fix · CNA xen (Xen) Fixed in next of 4.14.x
Fix · CNA xen (Xen) Fixed in next of 4.12.x

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Advisory · 2021-08-27
xen — FEDORA-2021-081f9bf5d2
7 records Highest priority Priority LOW 7 LOW
Other records, highest priority first
- TI-2021-09762 Incorrect authorization in xenPriority LOW 30
- TI-2021-09761 IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs…Priority LOW 30
- TI-2021-09760 IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs…Priority LOW 30
Show all 7 records → Advisory →
Advisory · 2021-08-27
xen — FEDORA-2021-d68ed12e46
7 records Highest priority Priority LOW 7 LOW
Other records, highest priority first
- TI-2021-09762 Incorrect authorization in xenPriority LOW 30
- TI-2021-09761 IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs…Priority LOW 30
- TI-2021-09760 IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs…Priority LOW 30
Show all 7 records → Advisory →

Show 2 more groups

Advisory · 2021-08-27
xen — FEDORA-2021-4f129cc0c1
7 records Highest priority Priority LOW 7 LOW
Other records, highest priority first
- TI-2021-09762 Incorrect authorization in xenPriority LOW 30
- TI-2021-09761 IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs…Priority LOW 30
- TI-2021-09760 IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs…Priority LOW 30
Show all 7 records → Advisory →
Advisory · 2021-08-27
xen — DSA-4977
7 records Highest priority Priority LOW 7 LOW
Other records, highest priority first
- TI-2021-09762 Incorrect authorization in xenPriority LOW 30
- TI-2021-09761 IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs…Priority LOW 30
- TI-2021-09760 IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs…Priority LOW 30
Show all 7 records → Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product

Red Hat

Timeline

2026-10-02 Threatist record created from CVE-2021-28697
2026-10-03 Alias added: GHSA-2h72-2hx7-mmcq

References

Advisory 6

TI-2012-00210 The x86-64 kernel system-call functionality in Xen 4.1.2 and earlier, as used in Citrix… CVSS 2.0HIGH 7.2
TI-2023-07042 Information disclosure through error messages in AMD Ryzen™ 3000 Series Desktop… CVSS 3.1MEDIUM 5.5
TI-2015-04333 The C+ mode offload emulation in the RTL8139 network card device model in QEMU, as used… CVSS 2.0HIGH 9.3
TI-2015-06741 The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows… CVSS 3.1CRITICAL 10.0
TI-2018-06436 A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures… CVSS 3.0HIGH 7.8
TI-2024-20522 x86: Incorrect logic for BTC/SRSO mitigations CVSS 3.1HIGH 7.5

See all 489 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences