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Vulnerabilities

Vulnerability · CVE-2021-0027

Vmware vSphere Web Client (FLEX/Flash) Unauthorized Arbitrary File Read Vulnerability

Published Jun 7, 2025 · catalog updated Jun 7, 2025 · VMware vSphere Web Client (FLEX/Flash)

Severity
Unknown—
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
Not in the current FIRST EPSS dataset
Remediation
Remediation guidance
Affected products
vendor VMware vSphere Web Client (FLEX/Flash)

Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: none. Reason: This candidate was in a CNA pool that was not assigned to any issues during 2021. Notes: none.

Technical analysis

Mechanism and impact are interpreted from ingested advisories — not independent exploit research.

  • CWE classification

    No CWE identifiers stored yet.

  • Prerequisites and impact

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

How to fix CVE-2021-0027

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2021-0027 is a unknown public vulnerability record for VMware vSphere Web Client (FLEX/Flash). CISA lists it as known exploited. Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether VMware vSphere Web Client (FLEX/Flash) is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: VMware vSphere Web Client (FLEX/Flash). Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: EPSS absent from current FIRST dataset (not low probability). CISA lists it as known exploited. Sources contributing to this record: cve_org, vulncheck_kev. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Related intelligence

  • Exploitation evidence

    Confirmed in CISA KEV since Jun 7, 2025. Listed in CISA KEV and VulnCheck KEV.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jun 7, 2025 · VulnCheck KEV

    Detected

    Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: none. Reason: This candidate was in a CNA pool that was not assigned to any issues during 2021. Notes: none.

  2. Jun 7, 2025 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Affected versions

Enter an installed version to get a verified affected / not-affected result against the ranges below.

  • vendor VMware vSphere Web Client (FLEX/Flash)version unspecified

Sources

  • CVE.orgVulnerability recordCVE-2021-0027

    Official CVE identifier

    cve.org
  • VulnCheck KEVConfirmed exploitationCVE-2021-0027

    Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: none. Reason: This candidate was in a CNA pool that was not assigned to any issues during 2021. Notes: none.

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.