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C Controller Module Setting And Monitoring ToolPlugin / extension · Mitsubishielectric

CVE-2021-20587

CRITICAL · 9.8 CVSS v3.1 Published 2021-02-19
Fix available
A fix is available. Upgrade to after 3.44w or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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
Heap-based buffer overflow vulnerability in Mitsubishi Electric FA Engineering Software (CPU Module Logging Configuration Tool versions 1.112R and prior, CW Configurator versions 1.011M and prior, Data Transfer versions 3.44W and prior, EZSocket versions 5.4 and prior, FR Configurator all versions, FR Configurator SW3 all versions, FR Configurator2 versions 1.24A and prior, GT Designer3 Version1(GOT1000) versions 1.250L and prior, GT Designer3 Version1(GOT2000) versions 1.250L and prior, GT SoftGOT1000 Version3 versions 3.245F and prior, GT SoftGOT2000 Version1 versions 1.250L and prior, GX Configurator-DP versions 7.14Q and prior, GX Configurator-QP all versions, GX Developer versions 8.506C and prior, GX Explorer all versions, GX IEC Developer all versions, GX LogViewer versions 1.115U and prior, GX RemoteService-I all versions, GX Works2 versions 1.597X and prior, GX Works3 versions 1.070Y and prior, iQ Monozukuri ANDON (Data Transfer) versions 1.003D and prior, iQ Monozukuri Process Remote Monitoring (Data Transfer) versions 1.002C and prior, M_CommDTM-HART all versions, M_CommDTM-IO-Link versions 1.03D and prior, MELFA-Works versions 4.4 and prior, MELSEC WinCPU Setting Utility all versions, MELSOFT EM Software Development Kit (EM Configurator) versions 1.015R and prior, MELSOFT Navigator versions 2.74C and prior, MH11 SettingTool Version2 versions 2.004E and prior, MI Configurator versions 1.004E and prior, MT Works2 versions 1.167Z and prior, MX Component versions 5.001B and prior, Network Interface Board CC IE Control utility versions 1.29F and prior, Network Interface Board CC IE Field Utility versions 1.16S and prior, Network Interface Board CC-Link Ver.2 Utility versions 1.23Z and prior, Network Interface Board MNETH utility versions 34L and prior, PX Developer versions 1.53F and prior, RT ToolBox2 versions 3.73B and prior, RT ToolBox3 versions 1.82L and prior, Setting/monitoring tools for the C Controller module (SW4PVC-CCPU) versions 4.12N and prior, and SLMP Data Collector versions 1.04E and prior) allows a remote unauthenticated attacker to cause a DoS condition on the software products, and possibly to execute a malicious code on the personal computer running the software products although it has not been reproduced, by spoofing MELSEC, GOT or FREQROL and returning crafted reply packets.

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 confidence

Heap-based buffer overflow vulnerability in multiple Mitsubishi Electric FA Engineering Software products when processing network packets. An unauthenticated remote attacker can spoof MELSEC, GOT or FREQROL devices and send crafted reply packets that overflow a heap buffer, causing denial of service and potentially enabling arbitrary code execution on the affected PC.

MitigationApply vendor patches when available; until then, isolate affected software systems on restricted network segments and block unauthorized device spoofing by implementing network access controls and device authentication.

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
C Controller Module Setting And Monitoring ToolPlugin / extension
Affected:all versions
Cpu Module Logging Configuration ToolPlugin / extension
Affected:<= 1.112r
Cw ConfiguratorApplication
Affected:<= 1.011m
Data TransferApplication
Affected:<= 3.44w
EzsocketApplication
Affected:all versions
Fr ConfiguratorApplication
Affected:all versions
Fr Configurator Sw3Application
Affected:all versions
Fr Configurator2Application
Affected:<= 1.24a

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
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 checks

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

  1. Identify installed Mitsubishi engineering software
    Check Windows Programs and Features or installed programs list for: C Controller Module Setting And Monitoring Tool, Cpu Module Logging Configuration Tool, Cw Configurator, Data Transfer, Ezsocket, Fr Configurator, Fr Configurator Sw3, or Fr Configurator2
    Affected if Any of these products are listed as installed
  2. Verify installed product versions
    Open each found product and check its About or Version information menu. Compare against: Cpu Module Logging Configuration Tool <= 1.112r, Cw Configurator <= 1.011m, Data Transfer <= 3.44w, Fr Configurator2 <= 1.24a. Note: C Controller Module Setting And Monitoring Tool, Ezsocket, Fr Configurator, Fr Configurator Sw3 are affected in ALL versions
    Affected if Version is at or below the listed thresholds, or product is any version of those with no version ceiling
  3. Determine if network communication features are active
    Check if the software has enabled network device communication features. Look for settings related to MELSEC, GOT, FREQROL, or Ethernet device connections in the product configuration
    Affected if Network device communication features are enabled and the software is running or configured to listen for device replies
  4. Check for running processes or services
    Open Task Manager or run 'tasklist' command and look for processes associated with the installed products (e.g., any executable from Mitsubishi engineering software folders in Program Files)
    Affected if Any affected Mitsubishi engineering software processes are currently running and listening on network ports

If any affected Mitsubishi engineering software is installed with a vulnerable version and has network communication features enabled, the environment is likely affected by this CVE.

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
Upgrade available Upgrade to a release after 3.44w
Interim mitigation

Apply vendor patches when available; until then, isolate affected software systems on restricted network segments and block unauthorized device spoofing by implementing network access controls and device authentication.

Fix this in C Controller Module Setting And Monitoring Tool Scoped from the published advisory
  • Consultation8.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,940
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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-2021-20587 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