CVE-2023-1618
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 · uneditedActive Debug Code vulnerability in Mitsubishi Electric Corporation MELSEC WS Series WS0-GETH00200 Serial number 2310 **** and prior allows a remote unauthenticated attacker to bypass authentication and illegally log into the affected module by connecting to it via telnet which is hidden function and is enabled by default when shipped from the factory. As a result, a remote attacker with unauthorized login can reset the module, and if certain conditions are met, he/she can disclose or tamper with the module's configuration or rewrite the firmware.
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 confidenceThe MELSEC WS Series WS0-GETH00200 contains a hidden debug telnet service enabled by default that allows remote unauthenticated attackers to bypass authentication and gain illegal access. This backdoor permits module reset and, under certain conditions, allows disclosure/tampering of configuration or firmware rewrite.
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
- Low
- Integrity
- High
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
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 interface or check the device label to confirm the model is WS0-GETH00200 from the MELSEC WS SeriesAffected if Device model is WS0-GETH00200 and running any firmware version
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Check if telnet port 23 is openRun a port scan against the device IP using nmap -p 23 <device_ip> or netcat nc -zv <device_ip> 23Affected if Port 23/telnet is open and responding on the device
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Verify telnet service accessibilityAttempt to connect to the device via telnet: telnet <device_ip> and observe if a debug or login prompt appears without authenticationAffected if Telnet connection succeeds and provides access without credentials or presents a debug menu
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Assess network exposureReview firewall rules, network segmentation, and external access lists to determine if the device telnet port is reachable from untrusted networks or the internetAffected if Device telnet port is accessible from untrusted networks, DMZ, or directly internet-facing
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Check for unexpected open portsPerform a full port scan (nmap -p- <device_ip>) to identify any other unexpected open ports that may indicate additional debug servicesAffected if Any unusual or undocumented ports are open on the device
A user is affected if they have a WS0-GETH00200 device with telnet port 23 accessible on their network, as the hidden debug service allows unauthenticated bypass of authentication.
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 dataImmediately network-segment or firewall the affected device to block telnet access (port 23), contact Mitsubishi Electric for firmware updates that remove the debug code, and audit industrial networks for exposed telnet services.
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-1618 — 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-2023-1618 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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