Modicon M221 FirmwareOperating system · Schneider Electric

CVE-2020-7565

HIGH · 7.3 CVSS v3.1 Published 2020-11-19
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
76/100
Remediation priority · High
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 CWE-326: Inadequate Encryption Strength vulnerability exists in Modicon M221 (all references, all versions) that could allow the attacker to break the encryption key when the attacker has captured the traffic between EcoStruxure Machine - Basic software and Modicon M221 controller.

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

The Modicon M221 PLC uses inadequate encryption strength for communications with EcoStruxure Machine - Basic software, allowing an attacker who captures network traffic to break the encryption key and potentially intercept or manipulate communications.

MitigationSince all versions are affected, contact Schneider Electric for firmware updates. In the interim, network segmentation and monitoring for suspicious traffic can reduce risk.

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
Modicon M221 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
Adjacent
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/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 Modicon M221 PLC devices on the network
    Scan the network for devices with vendor ID for Schneider Electric and product identification matching Modicon M221, or check PLC project files for M221 controller references
    Affected if A Modicon M221 PLC is present in the environment
  2. Confirm firmware version of the Modicon M221
    Connect to the PLC via EcoStruxure Machine - Basic or Unity Pro/SoMachine Basic and navigate to the firmware information section, or use the PLC programming software to read the controller properties
    Affected if The firmware version cannot be determined or is any version (all versions are affected)
  3. Identify EcoStruxure Machine - Basic software in use
    Check engineering workstations for installed software and identify EcoStruxure Machine - Basic or verify project files that use this software for M221 programming
    Affected if EcoStruxure Machine - Basic software is used to program or communicate with the PLC
  4. Inspect network traffic between PLC and engineering workstation
    Capture network traffic using a packet sniffer (such as Wireshark) on the network segment between the Modicon M221 and the workstation running EcoStruxure Machine - Basic; examine the encryption protocol and key exchange
    Affected if Unencrypted or weakly encrypted traffic is observed, or traffic uses a known weak encryption algorithm (e.g., static or short-key encryption)

A user is affected if a Modicon M221 PLC with any firmware version is present and communicates with EcoStruxure Machine - Basic software using inadequate encryption

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

Since all versions are affected, contact Schneider Electric for firmware updates. In the interim, network segmentation and monitoring for suspicious traffic can reduce risk.

Fix this in Modicon M221 Firmware Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA4.0 h
40.0 hours of engineering $7,000
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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-2020-7565 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