Read the docs
TI-2021-09758 Aliases CVE-2021-28692GHSA-23j5-p74r-rvqm

Improper privilege management in xen

Priority LOW 31CWE-269Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Privilege escalation
Confidentiality · integrity · availability
High · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-269.

Summary

inappropriate x86 IOMMU timeout detection / handling IOMMUs process commands issued to them in parallel with the operation of the CPU(s) issuing such commands. In the current implementation in Xen, asynchronous notification of the completion of such commands is not used. Instead, the issuing CPU spin-waits for the completion of the most recently issued command(s). Some of these waiting loops try to apply a timeout to fail overly-slow commands. The course of action upon a perceived timeout actually being detected is inappropriate: - on Intel hardware guests which did not originally cause the timeout may be marked as crashed, - on AMD hardware higher layer callers would not be notified of the issue, making them continue as if the IOMMU operation succeeded.

Why it matters now

EPSS 0.00287 21st percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
Xenxen4.13.x—No fix listedCNA
Xenxen4.14.x—No fix listedCNA
Xenxen4.15.x—No fix listedCNA
Xenxenxen-unstable—No fix listedCNA
Xenxen4.12.x—No fix listedCNA
Xenxen4.11.x—No fix listedCNA
  • xen VendorXen Affected 4.13.x Fixed in — No fix listed CNA
  • xen VendorXen Affected 4.14.x Fixed in — No fix listed CNA
  • xen VendorXen Affected 4.15.x Fixed in — No fix listed CNA
  • xen VendorXen Affected xen-unstable Fixed in — No fix listed CNA
  • xen VendorXen Affected 4.12.x Fixed in — No fix listed CNA
  • xen VendorXen Affected 4.11.x Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*3.2.0VulnerableXen
  • cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:* Versions 3.2.0 Vulnerable ·Xen

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-28692
  2. 2026-10-03 Alias added: GHSA-23j5-p74r-rvqm

References

Advisory 2

  • 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