CVE-2016-8368
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 · uneditedAn issue was discovered in Mitsubishi Electric Automation MELSEC-Q series Ethernet interface modules QJ71E71-100, all versions, QJ71E71-B5, all versions, and QJ71E71-B2, all versions. The affected Ethernet interface module is connected to a MELSEC-Q PLC, which may allow a remote attacker to connect to the PLC via Port 5002/TCP and cause a denial of service, requiring the PLC to be reset to resume operation. This is caused by an Unrestricted Externally Accessible Lock.
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 confidenceMitsubishi Electric MELSEC-Q series Ethernet interface modules (QJ71E71-100, QJ71E71-B5, QJ71E71-B2) contain an unrestricted externally accessible lock vulnerability. A remote attacker can connect to the PLC via Port 5002/TCP and trigger a denial of service condition that requires manual reset of the PLC to restore operation.
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 versionsall versionsall 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
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/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 Ethernet interface module modelLocate the physical module or check system documentation to determine the exact model number of the MELSEC-Q series Ethernet interface module (e.g., QJ71E71-100, QJ71E71-B5, or QJ71E71-B2)Affected if The module model is QJ71E71-100, QJ71E71-B5, or QJ71E71-B2
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Confirm firmware versionAccess the module configuration or firmware management interface to retrieve the installed firmware versionAffected if The module is running any firmware version (all versions are affected)
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Check if Port 5002/TCP is accessiblePerform a network port scan targeting the IP address of the affected module to determine if Port 5002/TCP is open and respondingAffected if Port 5002/TCP is open and reachable from an untrusted network segment
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Verify network exposureReview network segmentation and firewall rules to determine whether the PLC Ethernet module is directly accessible from external or untrusted networksAffected if The module is accessible from networks outside the trusted control system network without firewall protection
A user is affected if they have a QJ71E71-100, QJ71E71-B5, or QJ71E71-B2 module with Port 5002/TCP exposed to untrusted networks, as this allows remote attackers to trigger the denial of service condition.
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 dataIsolate affected Ethernet interface modules behind a firewall or air-gap to restrict unauthorized access to Port 5002/TCP. Contact Mitsubishi for firmware updates that address the unrestricted lock vulnerability.
- Consultation8.0 h
- Implementation16.0 h
- Testing8.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2016-8368 — 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-2016-8368 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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