# CVE-2020-3992: VMware ESXi OpenSLP Use-After-Free

> A malicious actor on the management network can trigger a use-after-free in OpenSLP to achieve remote code execution on VMware ESXi hosts.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 3 Nov 2021 (CISA KEV), used in ransomware
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Oct 2020
- **Updated:** 12 Aug 2026
- **Also known as:** GHSA-58ff-49fr-3jwf

## What is CVE-2020-3992?

CVE-2020-3992 is a critical use after free vulnerability in Vmware Cloud Foundation, published on 20 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OpenSLP as used in VMware ESXi (7.0 before ESXi_7.0.1-0.0.16850804, 6.7 before ESXi670-202010401-SG, 6.5 before ESXi650-202010401-SG) has a use-after-free issue. A malicious actor residing in the management network who has access to port 427 on an ESXi machine may be able to trigger a use-after-free in the OpenSLP service resulting in remote code execution.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2020-3992?

It affects 2 products.


Products: Vmware Cloud Foundation, Vmware Esxi.

## How do I fix CVE-2020-3992?

No fix has been published for CVE-2020-3992 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 3 May 2022.

## Is CVE-2020-3992 being exploited?

Yes. Attackers have exploited CVE-2020-3992 in the wild since at least 3 Nov 2021, including in ransomware campaigns.

Public exploit code:

- CVE-2020-3992 & CVE-2019-5544 (github_poc): https://github.com/dgh05t/VMware_ESXI_OpenSLP_PoCs
- Python / scapy module implementing SRVLOC/SLP protocol and scans for enabled OpenSLP services. (github_poc): https://github.com/HynekPetrak/CVE-2019-5544_CVE-2020-3992

## 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-2020-3992 and fix it if it is affected.

What it is: CVE-2020-3992 is a critical use after free vulnerability in Vmware Cloud Foundation, published on 20 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2020-3992 in the wild since at least 3 Nov 2021, including in ransomware campaigns.

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-2020-3992/ (Markdown: https://insights.sbomify.com/CVE-2020-3992/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3992
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3992
- OSV: https://osv.dev/vulnerability/CVE-2020-3992

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-3992/
Summaries are generated and may contain mistakes; the official description above is the record.