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CVE Record

CVE-2018-7821: An Environment (CWE-2) vulnerability exists in SoMachine Basic, all versions, and Modicon M221(all referenc...

An Environment (CWE-2) vulnerability exists in SoMachine Basic, all versions, and Modicon M221(all references, all versions prior to firmware V1.10.0.0) which could cause cycle time impact when flooding the M221 ethernet interface while the Ethernet/IP adapter is activated.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2018-7821 affects Schneider Electric SoMachine Basic and Modicon M221 environments. If the M221 Ethernet interface is flooded while the Ethernet/IP adapter is active, controller cycle time can be impacted. For an industrial process, that means degraded timing or performance rather than confirmed code execution.

Executive priority

Prioritize review for production networks where controller timing affects safety, availability, or throughput. This is not documented as actively exploited, but exposed industrial controllers with outdated firmware should be remediated through vendor guidance and network controls.

Technical view

The source bundle describes an Environment-class issue in SoMachine Basic, all versions, and Modicon M221 controllers before firmware V1.10.0.0. The documented trigger condition is Ethernet interface flooding when Ethernet/IP adapter functionality is enabled, causing cycle-time impact. No CVSS vector, CWE detail, or exploit proof is provided.

Likely exposure

Exposure is most likely where Modicon M221 controllers are reachable on Ethernet, use firmware earlier than V1.10.0.0, and have Ethernet/IP adapter capability enabled. SoMachine Basic is also listed as affected, but the bundle does not clarify its independent exposure path.

Exploitation context

The bundle does not report active exploitation, and KEV status is false. The described condition requires network access sufficient to flood the M221 Ethernet interface while Ethernet/IP adapter functionality is active. Treat this as an operational resilience risk in exposed or weakly segmented industrial networks.

Researcher notes

Evidence is limited: no CVSS, no detailed CWE list, and no public exploit status in the bundle. The key technical boundary is Ethernet reachability plus Ethernet/IP adapter activation. Avoid assuming impact beyond cycle-time degradation unless Schneider’s advisory provides more detail.

Mitigation direction

  • Check Schneider Electric advisory SEVD-2019-045-01 for product-specific guidance.
  • Update Modicon M221 firmware to V1.10.0.0 or later where applicable.
  • Review whether Ethernet/IP adapter functionality is required in each deployment.
  • Restrict Ethernet access to M221 controllers using industrial network segmentation.
  • Monitor controller performance for abnormal cycle-time degradation.

Validation and detection

  • Inventory SoMachine Basic and Modicon M221 deployments.
  • Record Modicon M221 firmware versions and controller references.
  • Confirm whether Ethernet/IP adapter functionality is enabled.
  • Verify controller Ethernet interfaces are not broadly reachable.
  • Check logs or monitoring for unexplained cycle-time impact.
Prepared
Confidence
medium
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2018-7821 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/aSoMachine Basic and Modicon M221, SoMachine Basic, all versions Modicon M221, all references, all versions prior to firmware V1.10.0.0SoMachine Basic and Modicon M221, SoMachine Basic, all versions Modicon M221, all references, all versions prior to firmware V1.10.0.0Listed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.