CVE-2016-20030
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 · uneditedZKTeco ZKBioSecurity 3.0 contains a user enumeration vulnerability that allows unauthenticated attackers to discover valid usernames by submitting partial characters via the username parameter. Attackers can send requests to the authLoginAction!login.do script with varying username inputs to enumerate valid user accounts based on application responses.
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 confidenceZKTeco ZKBioSecurity 3.0 contains a user enumeration vulnerability in the authLoginAction!login.do endpoint that allows unauthenticated attackers to discover valid usernames by submitting partial character sequences. The application returns distinguishable responses based on username validity, enabling attackers to harvest valid user accounts for further attacks.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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 checksWork through these to decide whether this CVE applies to you.
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Confirm ZKBioSecurity 3.0 is installedCheck the web application's HTTP headers, title, or fingerprint for 'ZKBioSecurity' or version identifier '3.0'Affected if The application identifies as ZKBioSecurity version 3.0
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Verify login endpoint existsAttempt to access the authLoginAction!login.do endpoint (typically at /login.do or within the web root path)Affected if The endpoint responds with a login form or accepts POST requests
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Test response differentiation for usernamesSend two POST requests to the login endpoint: one with a valid-looking username and one with an obviously invalid username, compare HTTP status codes and response contentAffected if Responses differ in error messages, timing, or status codes between valid and invalid usernames
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Check for enumeration via partial credentialsSubmit partial username strings (e.g., 'admin') to the endpoint and observe if the application provides different responses than for completely invalid stringsAffected if The application gives different responses for partial matches of existing usernames versus non-existent usernames
If ZKBioSecurity 3.0 is running and the login endpoint returns distinguishable responses for valid versus invalid usernames, the environment is affected by this user enumeration vulnerability.
Generated from the published advisory. Verify against your own configuration.
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 dataImplement uniform error messages for both invalid usernames and incorrect passwords to prevent enumeration, combined with rate limiting on the login endpoint to discourage automated attacks.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2016-20030 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2016-20030 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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