CVE-2020-3952 — Vcenter Server
CRITICALCVE-2020-3952 is a critical-severity (CVSS 9.8) Missing Authentication vulnerability in vmware vcenter server. It is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
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.
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2021-11-03. Federal agencies were required to remediate by 2022-05-03.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2020-3952.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-3952 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.
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.
Affected Products
vcenter servervmwareResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
VMware vCenter Server 6.7 - Authentication Bypass
by Photubias · Jun 1, 2020
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every vmware vcenter server deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2020-3952 yet — track the vmware vcenter server advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
How to detect CVE-2020-3952
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2020-3952 -u https://target- Template
- VMware vCenter Server LDAP Broken Access Control
- Severity
- critical
- Impact
- Unauthorized users may access sensitive functions, potentially leading to privilege escalation or data exposure.
- Remediation
- Apply the latest security patches and updates provided by VMware to address access control issues.
Template by ProjectDiscovery nuclei-templates (0x_Akoko), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2020-3952 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.