CVE-2021-22038

Administrator code execution via fixed-path binary replacement

Published Oct 29, 2021 · Updated Aug 3, 2024

Local privilege escalation in VMware InstallBuilder before 21.6.0 allows local users to execute code through a Windows uninstaller race. The uninstaller copies itself to a fixed, access-unrestricted temporary path and then executes that path, allowing its copied binary to be replaced before launch. Exploitation requires prior access to monitor the temporary directory and an uninstaller launched with Administrator privileges; resulting code runs in that privileged security context.

CVSS severity8.8
High
EPSS probability0.99%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Local privilege escalation in VMware InstallBuilder before 21.6.0 allows local users to execute code through a Windows uninstaller race. The uninstaller copies itself to a fixed, access-unrestricted temporary path and then executes that path, allowing its copied binary to be replaced before launch. Exploitation requires prior access to monitor the temporary directory and an uninstaller launched with Administrator privileges; resulting code runs in that privileged security context.

The record

CVE
CVE-2021-22038
Published
Oct 29, 2021
Updated
Aug 3, 2024
Vendor
VMware
Product
InstallBuilder
Classifications
CWE-330, T1574.005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 29, 2021CVE 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=All InstallBuilder versions prior to version 21.6.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

VMware · InstallBuilderversion=All InstallBuilder versions prior to version 21.6.0

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5NIST NVDAV:N/AC:L/Au:S/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-330Use of Insufficiently Random Values
T1574.005Hijack Execution Flow: Executable Installer File Permissions Weakness

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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