CVE-2021-22043

Privilege escalation via temporary-file TOCTOU

Published Feb 16, 2022 · Updated Aug 3, 2024

TOCTOU in settingsd in VMware ESXi 7.0 U1 through 7.0 U3 allows remote authenticated users to gain privileges via temporary files. settingsd checks a temporary file and later uses it without ensuring the checked object is unchanged, permitting a race that redirects a privileged write. Access to settingsd and successful race timing are required; arbitrary file writes can elevate privileges within the ESXi host.

CVSS severity8.2
High
EPSS probability1.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

TOCTOU in settingsd in VMware ESXi 7.0 U1 through 7.0 U3 allows remote authenticated users to gain privileges via temporary files. settingsd checks a temporary file and later uses it without ensuring the checked object is unchanged, permitting a race that redirects a privileged write. Access to settingsd and successful race timing are required; arbitrary file writes can elevate privileges within the ESXi host.

The record

CVE
CVE-2021-22043
Published
Feb 16, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-367, T1068
Attack vector
local
Privileges
authenticated

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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.2VMwareCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
6.0NISTAV:N/AC:M/Au:S/C:P/I:P/A:P
7.5NISTCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
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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