CVE-2021-32976
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 · uneditedFive buffer overflows in the built-in web server in Moxa NPort IAW5000A-I/O series firmware version 2.2 or earlier may allow a remote attacker to initiate a denial-of-service attack and execute arbitrary code.
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 confidenceFive buffer overflow vulnerabilities exist in the built-in web server of Moxa NPort IAW5000A-I/O series devices running firmware version 2.2 or earlier. These stack-based buffer overflows can be exploited remotely without authentication, allowing an attacker to cause denial-of-service conditions or achieve arbitrary code execution on the affected device.
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<= 2.2<= 2.2<= 2.2<= 2.2CVSS 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 modelCheck the physical device label or access the web interface to confirm the exact model number (e.g., NPort IAW5150A 6i/o, NPort IAW5150A 12i/o, NPort IAW5250A 6i/o, or NPort IAW5250A 12i/o).Affected if The model matches one of the four affected product names: Nport Iaw5150a 6i/o, Nport Iaw5150a 12i/o, Nport Iaw5250a 6i/o, or Nport Iaw5250a 12i/o.
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Determine the installed firmware versionLog into the device web interface and navigate to the System Settings or System Information page to view the firmware version. Alternatively, use the device's administrative console or SNMP to retrieve the firmware version.Affected if The firmware version is 2.2 or earlier (e.g., 2.2, 2.1, 2.0, 1.x).
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Confirm the built-in web server is enabledCheck the device network configuration to verify if the HTTP/HTTPS web server is enabled and listening on the network. This is typically found under Network Settings or Service Settings in the web interface.Affected if The web server is enabled and accessible from the network, making the device remotely exploitable.
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Assess network exposureDetermine if the device web interface is accessible from untrusted networks by reviewing firewall rules, VLAN configurations, or network segmentation policies.Affected if The device web interface is directly exposed to the internet or untrusted internal networks without firewall protection.
You are affected if you have a Moxa NPort IAW5150A or IAW5250A series device (6i/o or 12i/o variants) running firmware version 2.2 or earlier with the built-in web server enabled and 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 the vendor-supplied firmware update (version 2.3 or later). If patching is not immediately feasible, isolate affected devices behind a firewall or air-gap them from untrusted networks to reduce attack surface, as the vulnerability is network-exploitable.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-32976 — 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-2021-32976 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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