What is CVE-2020-3992?

CVE-2020-3992 is a critical-severity vulnerability in VMware Cloud Foundation, classified under Use After Free. CVSS score: 9.8/10. Published 2020-10-20.

How severe is CVE-2020-3992?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2020-3992 known to be exploited?

Yes. CVE-2020-3992 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 24 public proof-of-concept repositories are indexed.

Use After Free in VMware Cloud Foundation

CVE-2020-3992

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.

Vulnerability class: Use-After-Free

Published 2020-10-20 · last modified 2026-08-12.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.830 (99.7th percentile), scored 2026-10-16.

High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.830 · newest: 0.830 · change: 0.000

Affected products

VMware Cloud Foundation
VMware Esxi — versions 6.5, 6.7, 7.0.0
VMware Esxi — versions VMware ESXi (7.0 before ESXi_7.0.1-0.0.16850804, 6.7 before ESXi670-202010401-SG, 6.5 before ESXi650-202010401-SG)

Weakness classification (CWE)

CWE-416 — Use After Free

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2021-11-03. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2022-05-03.

Required action: Apply updates per vendor instructions.

Known ransomware campaign use: yes.

Public proof-of-concept exploits

References

www.vmware.com/security/advisories/VMSA-2020-0023.html (Patch, Vendor Advisory)
www.zerodayinitiative.com/advisories/ZDI-20-1377/ (VDB Entry, Third Party Advisory)
www.zerodayinitiative.com/advisories/ZDI-20-1385/ (VDB Entry, Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2020-3992?: CVE-2020-3992 is a critical-severity vulnerability in VMware Cloud Foundation, classified under Use After Free. CVSS score: 9.8/10. Published 2020-10-20.
How severe is CVE-2020-3992?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2020-3992 known to be exploited?: Yes. CVE-2020-3992 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 24 public proof-of-concept repositories are indexed.