Rj71en71 FirmwareOperating system · Mitsubishielectric

CVE-2022-40265

HIGH · 7.5 CVSS v3.1 Published 2022-11-30
Fix available
A fix is available. Upgrade to after 65 or later.
See remediation →
84/100
Remediation priority · High
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
Improper Input Validation vulnerability in Mitsubishi Electric Corporation MELSEC iQ-R Series RJ71EN71 Firmware version "65" and prior and Mitsubishi Electric Corporation MELSEC iQ-R Series R04/08/16/32/120ENCPU Network Part Firmware version "65" and prior allows a remote unauthenticated attacker to cause a Denial of Service condition by sending specially crafted packets. A system reset is required for recovery.

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

Improper input validation in Mitsubishi Electric MELSEC iQ-R Series RJ71EN71 and R04/08/16/32/120ENCPU network module firmware versions 65 and prior allows remote unauthenticated attackers to cause denial of service via specially crafted packets. Recovery requires a system reset.

MitigationUpdate affected devices to firmware version 66 or later. As an interim measure, restrict network access to these devices using firewalls or network segmentation since the vulnerability is exploitable remotely without 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
Rj71en71 FirmwareOperating system
Affected:<= 65
R04encpu FirmwareOperating system
Affected:<= 65
R08encpu FirmwareOperating system
Affected:<= 65
R16encpu FirmwareOperating system
Affected:<= 65
R32encpu FirmwareOperating system
Affected:<= 65
R120encpu FirmwareOperating system
Affected:<= 65

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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 checks

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

  1. Identify the network module model
    Access the PLC programming software (GX Works) or check the device's web interface to identify if the network module is an RJ71EN71 or R04ENCPU/R08ENCPU/R16ENCPU/R32ENCPU/R120ENCPU model.
    Affected if The device model matches one of the listed affected products (RJ71EN71, R04ENCPU, R08ENCPU, R16ENCPU, R32ENCPU, R120ENCPU).
  2. Check the firmware version
    Use the MELSOFT GX Works3 software or the device's built-in web interface to view the network module firmware version. Navigate to the module diagnostics or properties section.
    Affected if The displayed firmware version is 65 or lower.
  3. Verify network exposure
    Review network firewall rules and segmentation policies to determine if the affected network module is directly accessible from untrusted networks or the internet.
    Affected if The device has direct network exposure without firewall protection or network segmentation.
  4. Check for denial of service symptoms
    Review system logs and network monitoring data for unexplained resets, loss of communication, or system instability affecting the network module.
    Affected if The device exhibits recurring communication failures or requires manual resets that coincide with external network activity.

A user is affected if they have a RJ71EN71 or R04/08/16/32/120ENCPU network module running firmware version 65 or lower that is accessible from a network where remote attackers could send specially crafted packets.

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 65
Interim mitigation

Update affected devices to firmware version 66 or later. As an interim measure, restrict network access to these devices using firewalls or network segmentation since the vulnerability is exploitable remotely without authentication.

Fix this in Rj71en71 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
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2022-40265 — 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-2022-40265 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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