What is CVE-2020-3952?

CVE-2020-3952 is a critical-severity vulnerability in VMware Vcenter Server, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2020-04-10.

How severe is CVE-2020-3952?

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

Is CVE-2020-3952 known to be exploited?

Yes. CVE-2020-3952 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 62 public proof-of-concept repositories are indexed.

Auth bypass in VMware Vcenter Server

CVE-2020-3952

Under certain conditions, vmdir that ships with VMware vCenter Server, as part of an embedded or external Platform Services Controller (PSC), does not correctly implement access controls.

Vulnerability class: Broken Authentication

Published 2020-04-10 · last modified 2026-06-17.

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: 0.904 (99.8th percentile), scored 2026-10-19.

High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.904 · newest: 0.904 · change: 0.000

Affected products

VMware Vcenter Server — versions 6.7
VMware Vcenter Server — versions vCenter Server 6.7 (embedded or external PSC) prior to 6.7u3f is affected by CVE-2020-3952 if it was upgraded from a previous release line such as 6.0 or 6.5. Clean installations of vCenter Server 6.7 (embedded or external PSC) are not affected.

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

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.

Public proof-of-concept exploits

References

www.vmware.com/security/advisories/VMSA-2020-0006 (Broken Link, Vendor Advisory)
packetstormsecurity.com/files/157896/VMware-vCenter-Server-6.7-Authentication-B… (Exploit, VDB Entry, Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2020-3952?: CVE-2020-3952 is a critical-severity vulnerability in VMware Vcenter Server, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2020-04-10.
How severe is CVE-2020-3952?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2020-3952 known to be exploited?: Yes. CVE-2020-3952 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 62 public proof-of-concept repositories are indexed.