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Nuclias ConnectApplication · Dlink

CVE-2025-34255

MEDIUM · 5.3 CVSS v3.1 Published 2025-10-16
Fix available
A fix is available. Upgrade to after 1.3.1.4 or later.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable 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
D-Link Nuclias Connect firmware versions <= 1.3.1.4 contain an observable response discrepancy vulnerability. The application's 'Forgot Password' endpoint returns distinct JSON responses depending on whether the supplied email address is associated with an existing account. Because the responses differ in the `data.exist` boolean value, an unauthenticated remote attacker can enumerate valid email addresses/accounts on the server. NOTE: D-Link states that a fix is under development.

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 · high confidence

D-Link Nuclias Connect firmware versions <= 1.3.1.4 have an observable response discrepancy in the 'Forgot Password' endpoint. The application returns different JSON responses indicating whether a supplied email address exists in the system via the `data.exist` boolean field, allowing unauthenticated attackers to enumerate valid user accounts.

MitigationUntil the vendor releases a firmware update, consider implementing rate limiting on the forgot password endpoint or using generic error messages that do not reveal account existence. The long-term fix requires a firmware patch that standardizes the response to not disclose account existence.

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
Nuclias ConnectApplication
Affected:<= 1.3.1.4

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
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

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

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. Confirm D-Link Nuclias Connect is deployed
    Identify if D-Link Nuclias Connect software is running in your environment. Check running services, web applications, or the admin interface on relevant servers.
    Affected if D-Link Nuclias Connect is not installed in your environment (not affected)
  2. Check installed firmware version
    Access the Nuclias Connect admin panel or system settings to determine the firmware version. Look for a version display in the dashboard or system information section.
    Affected if Firmware version is 1.3.1.4 or lower, making the version vulnerable
  3. Test Forgot Password endpoint for account disclosure
    Send a POST request to the Forgot Password endpoint (commonly /api/forgot-password or similar) with a test email address. Inspect the JSON response for the `data.exist` field.
    Affected if The response contains a `data.exist` boolean that returns true for valid email addresses and false for invalid ones, exposing account existence

Your environment is affected if D-Link Nuclias Connect firmware version is 1.3.1.4 or lower and the Forgot Password endpoint reveals account existence through the `data.exist` field in the JSON response.

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.

dbcve · scoped
Upgrade available Upgrade to a release after 1.3.1.4
Interim mitigation

Until the vendor releases a firmware update, consider implementing rate limiting on the forgot password endpoint or using generic error messages that do not reveal account existence. The long-term fix requires a firmware patch that standardizes the response to not disclose account existence.

Recommended fix High confidence
  1. Monitor D-Link support announcements (supportannouncement.us.dlink.com) for the availability of the security patch for CVE-2025-34255
  2. Implement rate limiting on the 'Forgot Password' endpoint to slow down email enumeration attacks
  3. Consider implementing CAPTCHA or account lockout policies for repeated password reset requests
  4. Restrict network access to the Nuclias Connect management interface to trusted networks only if possible

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Nuclias Connect Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
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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-2025-34255 in production — separate from our analysis above.

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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
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