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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)

Patch now

CVE-2021-0027 is in the CISA known-exploited catalog. Confirm VMware vSphere Web Client (FLEX/Flash) against the vendor advisory and apply that fix. The CVSS score does not change the priority.

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

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

How to fix CVE-2021-0027

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2021-0027 is in the CISA known-exploited catalog. Confirm VMware vSphere Web Client (FLEX/Flash) against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

What should an analyst verify?

No weakness class is stored. EPSS is absent from the current FIRST dataset. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

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.

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.