Modicom M340 FirmwareOperating system · Schneider Electric

CVE-2018-7804

MEDIUM · 6.1 CVSS v3.0 Published 2018-12-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

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 · unedited
A URL Redirection to Untrusted Site vulnerability exists in the embedded web servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200 where a user clicking on a specially crafted link can be redirected to a URL of the attacker's choosing.

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 · moderate confidence

Open redirect vulnerability in the embedded web servers of Modicon M340, Premium, Quantum PLCs and BMXNOR0200. An attacker can craft a malicious link that redirects users to an arbitrary website of their choosing, potentially leading to phishing attacks or credential theft.

MitigationApply vendor-supplied firmware updates for the affected PLCs. If immediate patching is not possible, disable the embedded web server or implement network segmentation to restrict access.

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
Modicom M340 FirmwareOperating system
Affected:all versions
Modicom Premium FirmwareOperating system
Affected:all versions
Modicom Quantum FirmwareOperating system
Affected:all versions
Modicom Bmxnor0200h FirmwareOperating system
Affected:all versions

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
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the PLC model
    Check the device labeling, firmware identification, or management interface to confirm the model is one of: Modicon M340, Premium, Quantum, or BMXNOR0200
    Affected if The model matches any of the four affected PLC families
  2. Determine if embedded web server is enabled
    Access the PLC programming software (e.g., Unity Pro, Somachine) or PLC management interface and check the web server configuration settings to see if the embedded web server is turned on
    Affected if The embedded web server feature is enabled in the PLC configuration
  3. Verify web server is accessible
    Attempt to reach the PLC IP address on HTTP (port 80) or HTTPS (port 443) from an authorized network segment
    Affected if The web interface responds and is reachable on the network
  4. Test for open redirect behavior
    Send a crafted request to the web server with a redirect parameter pointing to an external domain (e.g., /something?redirect=http://malicious.com) and observe if the server returns a 30x redirect to the arbitrary URL
    Affected if The web server accepts and follows redirects to user-controlled external domains

You are affected if you have a Modicon M340, Premium, Quantum, or BMXNOR0200 PLC with the embedded web server enabled and accessible, as all firmware versions contain the open redirect vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor-supplied firmware updates for the affected PLCs. If immediate patching is not possible, disable the embedded web server or implement network segmentation to restrict access.

Fix this in Modicom M340 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-7804 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-7804 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data