CVE-2016-4503
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 · uneditedMoxa Device Server Web Console 5232-N allows remote attackers to bypass authentication, and consequently modify settings and data, via vectors related to reading a cookie parameter containing a UserId value.
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 confidenceMoxa Device Server Web Console 5232-N contains an authentication bypass vulnerability where remote attackers can gain unauthorized access by manipulating or reading a cookie parameter containing a UserId value. This allows attackers to bypass the authentication mechanism entirely and modify device settings and data.
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 dataall versionsCVSS 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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Identify the device modelAccess the device web console or check the device label/serial number to confirm it is a Moxa Device Server Web Console 5232-NAffected if The device is a Moxa 5232-N model
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Check the firmware versionLog into the web console and navigate to System Settings or System Information to view the firmware version, or use the device's command-line interface if availableAffected if Any firmware version is present (all versions are affected)
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Verify web console is accessibleAttempt to access the device web interface via HTTP/HTTPS on the configured port (typically 80 or 443) from a network locationAffected if The web console is reachable over the network
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Test for authentication bypassUsing a web browser or HTTP tool, attempt to access protected pages without credentials, or modify the UserId cookie parameter to see if authentication can be bypassedAffected if Access to protected device settings is granted without valid authentication credentials
You are affected if you have a Moxa Device Server Web Console 5232-N with any firmware version and the web interface is network-accessible.
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 dataApply vendor firmware update if available; as an interim compensating control, restrict network access to the web console using firewall rules or network segmentation to limit exposure to untrusted networks.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-4503 — 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-2016-4503 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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- 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
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