# CVE-2021-22043: Race condition in VMware ESXi and VMware Cloud Foundation

> A local attacker with access to settingsd can exploit a TOCTOU race condition in temporary file handling to escalate privileges and write arbitrary files.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Feb 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-27hx-pvj5-2hqg

## What is CVE-2021-22043?

CVE-2021-22043 is a high-severity vulnerability in Vmware Esxi, published on 16 Feb 2022. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

VMware ESXi contains a TOCTOU (Time-of-check Time-of-use) vulnerability that exists in the way temporary files are handled. A malicious actor with access to settingsd, may exploit this issue to escalate their privileges by writing arbitrary files.

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

## Which versions are affected by CVE-2021-22043?

It affects 2 products.


Products: Vmware Esxi, Vmware Fusion.

## How do I fix CVE-2021-22043?

No fix has been published for CVE-2021-22043 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-22043 being exploited?

There is no known exploitation of CVE-2021-22043 in the wild and no public exploit code.

## Other vulnerabilities in Vmware Esxi

- [CVE-2026-41709](https://insights.sbomify.com/CVE-2026-41709/): Broadcom VMWare ESX Insufficient Logging (low 2.7, exploited in the wild)
- [CVE-2019-5521](https://insights.sbomify.com/CVE-2019-5521/): Information disclosure in VMware ESXi (critical 9.6)
- [CVE-2024-22252](https://insights.sbomify.com/CVE-2024-22252/): Use-after-free vulnerability (critical 9.3)
- [CVE-2020-3955](https://insights.sbomify.com/CVE-2020-3955/): Cross-site scripting in ESXi (critical 9.3)
- [CVE-2010-4573](https://insights.sbomify.com/CVE-2010-4573/): Auth bypass in n/a (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-22043 and fix it if it is affected.

What it is: CVE-2021-22043 is a high-severity vulnerability in Vmware Esxi, published on 16 Feb 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-22043 in the wild and no public exploit code.

Affected product: Vmware Esxi. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-22043/ (Markdown: https://insights.sbomify.com/CVE-2021-22043/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22043
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22043
- OSV: https://osv.dev/vulnerability/CVE-2021-22043

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-22043/
Summaries are generated and may contain mistakes; the official description above is the record.