CVE-2020-3952 — Under certain conditions, vmdir that ships with VMware vCenter Server, as part of an…¶

Key facts

CVE-2020-3952 is a Critical (9.8) vulnerability: Under certain conditions, vmdir that ships with VMware vCenter Server, as part of an…. This entry ships a detection-only PoC and a Docker test lab. It is on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2021-11-03), confirming active exploitation in the wild.

Actively exploited — on the CISA KEV catalog

CVE-2020-3952 is listed on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2021-11-03), confirming exploitation in the wild. Federal remediation deadline: 2022-05-03. Prioritise patching and deploy the detection and prevention rules below.


CVE	CVE-2020-3952
Severity	Critical (9.8)
CISA KEV	Actively exploited (added 2021-11-03)
Detection / prevention	—
PoC	poc.py
Source	2020/CVE-2020-3952/

Details¶

English | 한국어

Description¶

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 Details¶

Property	Value
CVE ID	CVE-2020-3952
CVSS Score	9.8

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2020/CVE-2020-3952/poc.py

Usage¶

# Run PoC against target
python3 poc.py --target <TARGET_URL>

# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>

⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.

Test Lab¶

This repository includes a Docker-based test environment with both vulnerable and patched applications.

Quick Start¶

# Clone and navigate to CVE directory
cd CVE-2020-3952

# Start both applications
docker-compose up -d

# Run tests
./run-tests.sh    # Linux/Mac
./run-tests.ps1   # Windows PowerShell

Application Endpoints¶

Application	URL	Status
Vulnerable App	http://localhost:8080	Shows vulnerability
Patched App	http://localhost:8081	Demonstrates fix

Directory Structure¶

├── README.md           # English documentation
├── README_KO.md        # Korean documentation
├── poc.py              # PoC detection script
├── docker-compose.yml  # Container orchestration
├── run-tests.sh        # Linux/Mac test runner
├── run-tests.ps1       # Windows test runner
├── vulnerable-app/     # Vulnerable version
│   ├── app.py
│   ├── Dockerfile
│   └── requirements.txt
└── patched-app/        # Fixed version
    ├── app.py
    ├── Dockerfile
    └── requirements.txt

References¶

http://packetstormsecurity.com/files/157896/VMware-vCenter-Server-6.7-Authentication-Bypass.html
https://www.vmware.com/security/advisories/VMSA-2020-0006
http://packetstormsecurity.com/files/157896/VMware-vCenter-Server-6.7-Authentication-Bypass.html
https://www.vmware.com/security/advisories/VMSA-2020-0006
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3952

Generated by PoC Generator on 2026-07-01T14:53:43.712127147

Frequently asked questions¶

What is CVE-2020-3952?¶

CVE-2020-3952 is a Critical (9.8) vulnerability: Under certain conditions, vmdir that ships with VMware vCenter Server, as part of an…. This entry ships a detection-only PoC and a Docker test lab. It is on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2021-11-03), confirming active exploitation in the wild.

How do I detect CVE-2020-3952?¶

Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.

How do I block or mitigate CVE-2020-3952?¶

Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.

Is CVE-2020-3952 actively exploited?¶

Yes. CVE-2020-3952 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, added 2021-11-03, which means it has been exploited in the wild. CISA set a federal remediation deadline of 2022-05-03. Prioritise patching and deploy the detection and prevention rules above.

For authorized security testing and research only. See the full source and NVD record.