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Wyse ThinosOperating system · Dell

CVE-2021-21532

MEDIUM · 6.3 CVSS v3.1 Published 2021-04-02
Fix available
A fix is available. Upgrade to 8.6 or later.
See remediation →
68/100
Remediation priority · Elevated
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Dell Wyse ThinOS 8.6 MR9 contains remediation for an improper management server validation vulnerability that could be potentially exploited to redirect a client to an attacker-controlled management server, thus allowing the attacker to change the device configuration or certificate file.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Dell Wyse ThinOS 8.6 MR9 contains an improper management server validation vulnerability where the thin client fails to adequately validate the legitimacy of the management server it connects to. This allows an attacker to perform a man-in-the-middle attack, redirecting the client to an attacker-controlled management server where they can modify device configuration settings or replace certificate files.

MitigationApply the vendor-supplied patch/update for ThinOS 8.6 MR9 to remediate the improper management server validation. Ensure management server communications are over trusted networks and consider implementing additional certificate validation controls.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Wyse ThinosOperating system
Affected:< 8.6= 8.6

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify ThinOS version
    Access the ThinOS admin interface or check the system information page to find the current firmware/OS version. This is typically found under 'System Setup' > 'General' or on the login screen. Alternatively, check via CLI if available using 'version' or 'sysinfo' command.
    Affected if The installed version is 8.6 or any version below 8.6 (e.g., 8.5, 8.4, etc.)
  2. Verify management server feature is configured
    Check if any management server (WMS, Dell Wyse Management Suite, or third-party management server) is enabled on the device. Navigate to 'System Setup' > 'Management Server' or similar section in the ThinOS admin panel. Look for configured server URLs or IP addresses.
    Affected if A management server is configured and the ThinOS version is 8.6 or below (the vulnerable version range)
  3. Inspect management server connection settings
    Examine the configured management server URL or IP address in the ThinOS management server settings. Check if the server address is pointing to an expected, internal/trusted location. Look for any suspicious or unexpected server entries.
    Affected if The configured management server points to an untrusted or unexpected network location, combined with a vulnerable version (8.6 or below)
  4. Review SSL/TLS certificate validation settings
    Check the ThinOS management server configuration for certificate validation options. Look for settings related to 'Validate Server Certificate', 'Certificate Verification', or similar SSL/TLS validation controls within the management server configuration section.
    Affected if Certificate validation is disabled or set to 'None', and the ThinOS version is 8.6 or below

A user is affected if their ThinOS device is running version 8.6 or any version below 8.6 AND has a management server configured, as the vulnerability allows redirection to attacker-controlled servers when the client validates the management server improperly.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 8.6 or later
Fixed in 8.6
Interim mitigation

Apply the vendor-supplied patch/update for ThinOS 8.6 MR9 to remediate the improper management server validation. Ensure management server communications are over trusted networks and consider implementing additional certificate validation controls.

Fix this in Wyse Thinos Scoped from the published advisory
  • Consultation2.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,290
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,664.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-21532 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data