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

Source: https://junglewise.ai/threats/cve-2020-3992-vmware-esxi-openslp-use-after-free-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-11-03. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2020-3992 · Severity: critical · CVSS 9.8 · Exploited in the wild · Published 2021-11-03

OpenSLP as used in VMware ESXi contains a use-after-free vulnerability in the OpenSLP service. A remote attacker with access to port 427 on the management network can exploit this to execute arbitrary code on the host.

Technologies: [VMware ESXi](https://junglewise.ai/threats/technologies/esxi). Vendors: [VMware](https://junglewise.ai/threats/vendors/vmware).

## Quick answers

**Is CVE-2020-3992 exploited in the wild?** Yes. CVE-2020-3992 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.

**How severe is CVE-2020-3992?** Critical severity, with a CVSS score of 9.8, published 3 November 2021.

**Which products and versions are affected?** VMware ESXi 7.0 before ESXi_7.0.1-0.0.16850804; VMware ESXi 6.7 before ESXi670-202010401-SG; VMware ESXi 6.5 before ESXi650-202010401-SG.

**Is there a fix for CVE-2020-3992?** A patch was published on 2020-10-20: Vendor released patches for ESXi 6.5, 6.7, and 7.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2020-3992 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2020-3992?** Check whether you run VMware ESXi. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- VMware ESXi 7.0 before ESXi_7.0.1-0.0.16850804
- VMware ESXi 6.7 before ESXi670-202010401-SG
- VMware ESXi 6.5 before ESXi650-202010401-SG

## Timeline

- 2020-10-20: patched: Vendor released patches for ESXi 6.5, 6.7, and 7.0.
- 2021-11-03: disclosed: NVD publication date.
- 2021-11-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog.
- 2021-11-03: exploited: Confirmed as exploited in the wild per CISA KEV catalog.

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