CVE-2020-3952Known exploitationPublic exploitNetwork attack vector

Unauthenticated credential disclosure via vmdir access controls

Published Apr 10, 2020 · Updated Oct 21, 2025

Improper access control in VMware vCenter Server 6.7 upgraded from earlier releases allows remote attackers to obtain administrative credentials via vmdir on port 389. The vmdir service applies legacy ACL behavior that permits unauthenticated directory operations to read sensitive entries and can enable attacker-controlled administrative accounts. Exploitation requires network access to the directory service; the resulting disclosure can compromise vCenter and dependent authentication services, with integrity and availability impact also reported by VMware.

CVSS severity10.0
Critical
EPSS probability90.38%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in VMware vCenter Server 6.7 upgraded from earlier releases allows remote attackers to obtain administrative credentials via vmdir on port 389. The vmdir service applies legacy ACL behavior that permits unauthenticated directory operations to read sensitive entries and can enable attacker-controlled administrative accounts. Exploitation requires network access to the directory service; the resulting disclosure can compromise vCenter and dependent authentication services, with integrity and availability impact also reported by VMware.

The record

CVE
CVE-2020-3952
Published
Apr 10, 2020
Updated
Oct 21, 2025
Vendor
VMware
Product
VMware vCenter Server
Classifications
CWE-306, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 10, 2020CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2021Exploitation reportedCISA KEV active exploitation listing
  3. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=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.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

VMware · VMware vCenter Serverversion=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.

Published CVSS scores

6.8NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
10.0VMwareCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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