CVE intelligence and bounded remediation

CVE-2019-6820 — Schneider-Electric Modicon M100 Firmware security vulnerability

High CVSS 8.2

A CWE-306: Missing Authentication for Critical Function vulnerability exists which could cause a modification of device IP configuration (IP address, network mask and gateway IP address) when a specific Ethernet frame is received in all versions of: Modicon M100, Modicon M200, Modicon M221, ATV IMC drive controller, Modicon M241, Modicon M251, Modicon M258, Modicon LMC058, Modicon LMC078, PacDrive Eco ,PacDrive Pro, PacDrive Pro2

Severity
High
CVSS
8.2 (3.1)
Published
2019-05-22
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-306

Affected products

  • schneider-electric / modicon_m100_firmware
  • schneider-electric / modicon_m200_firmware
  • schneider-electric / modicon_m221_firmware
  • schneider-electric / atv_imc_drive_controller_firmware
  • schneider-electric / modicon_m241_firmware
  • schneider-electric / modicon_m251_firmware

Showing 6 representative product identities from 12 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Authentication bypass and missing authentication

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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