TI-2021-09764 Aliases CVE-2021-28698 GHSA-2g34-x978-mw32

Infinite loop in xen

LOW 25CWE-835Published 2021-08-27 · Updated 2024-08-03

Key facts

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

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-835.

Summary

long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In the process of carrying out certain actions, Xen would iterate over all such entries, including ones which aren't in use anymore and some which may have been created but never used. If the number of entries for a given domain is large enough, this iterating of the entire table may tie up a CPU for too long, starving other domains or causing issues in the hypervisor itself. Note that a domain may map its own grants, i.e. there is no need for multiple domains to be involved here. A pair of "cooperating" guests may, however, cause the effects to be more severe.

Why it matters now

EPSS 0.00348 28th percentileScored 2026-11-07

Fix Fixed xen (Xen): next of xen-unstable

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

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

CPE configurations NVD · 5

CPE	Versions	Role	Vendor
cpe:2.3:o:xen:xen::::::::	3.2.0	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 3.2.0 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 xen-unstable

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-2021-09763 Race condition in xenPriority LOW 34
- 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
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-2021-09763 Race condition in xenPriority LOW 34
- 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
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-2021-09763 Race condition in xenPriority LOW 34
- 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
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-2021-09763 Race condition in xenPriority LOW 34
- 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
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-2021-28698
2026-10-03 Alias added: GHSA-2g34-x978-mw32

References

Advisory 7

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