# CVE-2020-3981: Information disclosure in VMware ESXi, Workstation, Fusion

> A time-of-check time-of-use flaw in ACPI allows attackers with VM admin access to leak memory from the host vmx process.

- **Severity:** Medium 5.8 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Oct 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-9v5h-wgx5-jxxj

## What is CVE-2020-3981?

CVE-2020-3981 is a medium-severity vulnerability in Vmware Cloud Foundation, published on 20 Oct 2020. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

VMware ESXi (7.0 before ESXi_7.0.1-0.0.16850804, 6.7 before ESXi670-202008101-SG, 6.5 before ESXi650-202007101-SG), Workstation (15.x), Fusion (11.x before 11.5.6) contain an out-of-bounds read vulnerability due to a time-of-check time-of-use issue in ACPI device. A malicious actor with administrative access to a virtual machine may be able to exploit this issue to leak memory from the vmx process.

Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2020-3981?

It affects 4 products.


Products: Vmware Cloud Foundation, Vmware Esxi, Vmware Fusion, Vmware Workstation.

## How do I fix CVE-2020-3981?

No fix has been published for CVE-2020-3981 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3981 being exploited?

There is no known exploitation of CVE-2020-3981 in the wild and no public exploit code.

## Other vulnerabilities in Vmware Cloud Foundation

- [CVE-2024-38812](https://insights.sbomify.com/CVE-2024-38812/): VMware vCenter Server Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-37079](https://insights.sbomify.com/CVE-2024-37079/): Broadcom VMware vCenter Server Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2022-22954](https://insights.sbomify.com/CVE-2022-22954/): VMware Workspace ONE Access and Identity Manager Server-Side Template Injection (critical 9.8, exploited in the wild)
- [CVE-2021-22005](https://insights.sbomify.com/CVE-2021-22005/): VMware vCenter Server File Upload (critical 9.8, exploited in the wild)
- [CVE-2021-21985](https://insights.sbomify.com/CVE-2021-21985/): VMware vCenter Server Improper Input Validation (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3981 and fix it if it is affected.

What it is: CVE-2020-3981 is a medium-severity vulnerability in Vmware Cloud Foundation, published on 20 Oct 2020. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-3981 in the wild and no public exploit code.

Affected product: Vmware Cloud Foundation. 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-2020-3981/ (Markdown: https://insights.sbomify.com/CVE-2020-3981/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3981
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3981
- OSV: https://osv.dev/vulnerability/CVE-2020-3981

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-3981/
Summaries are generated and may contain mistakes; the official description above is the record.