CVE intelligence and bounded remediation

CVE-2018-4838 — Siemens En100 Ethernet Module Iec 104 Firmware security vulnerability

High CVSS 7.5

A vulnerability has been identified in EN100 Ethernet module IEC 61850 variant (All versions < V4.30), EN100 Ethernet module DNP3 variant (All versions < V1.04), EN100 Ethernet module PROFINET IO variant (All versions), EN100 Ethernet module Modbus TCP variant (All versions), EN100 Ethernet module IEC 104 variant (All versions < V1.22). The web interface (TCP/80) of affected devices allows an unauthenticated user to upgrade or downgrade the firmware of the device, including to older versions with known vulnerabilities.

Severity
High
CVSS
7.5 (3.0)
Published
2018-03-08
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-306

Affected products

  • siemens / en100_ethernet_module_iec_104_firmware
  • siemens / en100_ethernet_module_dnp3_firmware
  • siemens / en100_ethernet_module_modbus_tcp_firmware
  • siemens / en100_ethernet_module_profinet_io_firmware
  • siemens / en100_ethernet_module_iec_61850_firmware

Matched remediation archetype

Authentication bypass and missing authentication

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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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