---
id: "CVE-2020-3952"
kind: "vulnerability"
aliases: ["CVE-2020-3952"]
title: "VMware vCenter Server: VMware vCenter Server Information Disclosure Vulnerability"
severity: "critical"
cvss: 9.8
epss: 0.90384
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "VMware vCenter Server", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "infrastructure", "on-prem", "self-hosted", "vcenter", "vmware"]
not_affected_if: ["managed-hosting", "port-389-not-reachable"]
published_at: "2020-04-10T14:15:12+00:00"
first_seen_at: "2026-10-23T19:11:53+00:00"
updated_at: "2026-10-23T20:29:33+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-3952", "first_seen_at": "2026-10-23T19:11:53+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2020-3952", "first_seen_at": "2026-10-23T19:13:43+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-3952", "first_seen_at": "2026-10-23T19:35:23+00:00"}]
---

# VMware vCenter Server: VMware vCenter Server Information Disclosure Vulnerability

VMware vCenter Server's embedded VMware Directory Service (vmdir) does not enforce access controls correctly when the Platform Services Controller is in use, so anyone who can reach port 389 can pull sensitive directory information. CISA lists this as actively exploited in the wild.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:VMware vCenter Server affected ? fixed ?

## How to check

Check whether the vCenter Server build is older than the fixed release in VMware's advisory (version unknown from sources).
Find hosts that expose TCP 389 to untrusted networks, e.g. with a port scan from outside the management network.

## Fix

Apply the VMware vCenter Server update that addresses CVE-2020-3952 per the vendor advisory (version unknown from sources).
Restrict TCP 389 on vCenter/PSC hosts to required management hosts only.

## Timeline

- 2026-10-23T19:11:53+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-3952
- 2026-10-23T19:13:43+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2020-3952
- 2026-10-23T19:35:23+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2020-3952

## From the sources

VMware vCenter Server contains an information disclosure vulnerability in the VMware Directory Service (vmdir) when the Platform Services Controller (PSC) does not correctly implement access controls. Successful exploitation allows an attacker with network access to port 389 to extract sensitive information.

CISA required action: Apply updates per vendor instructions.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_