CVE-2021-22041

Host VMX code execution via UHCI double fetch

Published Feb 16, 2022 · Updated Aug 3, 2024

Double fetch in the UHCI USB controller in VMware ESXi, Workstation, and Fusion allows guest OS users to execute code in the host VMX process. VMware identifies the UHCI emulation path as the locus but does not disclose which guest-controlled value is fetched twice or how the inconsistent reads corrupt execution. Exploitation requires local administrative privileges in the guest and an isochronous USB endpoint attached to that virtual machine, after which code runs with the host VMX process's permissions.

CVSS severity8.4
High
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Double fetch in the UHCI USB controller in VMware ESXi, Workstation, and Fusion allows guest OS users to execute code in the host VMX process. VMware identifies the UHCI emulation path as the locus but does not disclose which guest-controlled value is fetched twice or how the inconsistent reads corrupt execution. Exploitation requires local administrative privileges in the guest and an isochronous USB endpoint attached to that virtual machine, after which code runs with the host VMX process's permissions.

The record

CVE
CVE-2021-22041
Published
Feb 16, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Feb 16, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.4VMwareCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
6.7NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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