CVEs / CVE-2020-3992

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

Known exploited in the CISA KEV catalog since 3 Nov 2021
critical 9.8 CVSS 3.1 (NVD)
EPSS 83% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
Last changed at its sources 12 Aug 2026

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Summary

VMware ESXi OpenSLP contains a use-after-free vulnerability that allows an attacker residing in the management network with access to port 427 to perform remote code execution.
CISA, Known Exploited Vulnerabilities catalog

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.
The CVE record, via NVD · published 20 Oct 2020 · NVD status: Analyzed

Affected and fixed versions

As stated by the CVE record (from the CNA)
Product	Affected	Fixed in
n/a VMware ESXi	VMware ESXi (7.0 before ESXi_7.0.1-0.0.16850804, 6.7 before ESXi670-202010401-SG, 6.5 before ESXi650-202010401-SG)	—

Exploitation

In CISA KEV since	3 Nov 2021
Due date for US federal agencies	3 May 2022
Used in ransomware campaigns	Known
Required action	Apply updates per vendor instructions.

Severity

CVSS 3.1	9.8 critical `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Scored by NVD
Weakness	CWE-416

References

CVE-2020-3992 on NVD
CVE-2020-3992 in the CISA KEV catalog
https://www.vmware.com/security/advisories/VMSA-2020-0023.html Patch, Vendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-20-1377/ Third Party Advisory, VDB Entry
https://www.zerodayinitiative.com/advisories/ZDI-20-1385/ Third Party Advisory, VDB Entry
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3992 US Government Resource

Sources

Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.

This product uses data from the NVD API but is not endorsed or certified by the NVD.