CVE intelligence and bounded remediation

CVE-2023-27396 — Omron Cs1W-Eip21 Firmware security vulnerability

Critical CVSS 9.8

FINS (Factory Interface Network Service) is a message communication protocol, which is designed to be used in closed FA (Factory Automation) networks, and is used in FA networks composed of OMRON products. Multiple OMRON products that implement FINS protocol contain following security issues -- (1)Plaintext communication, and (2)No authentication required. When FINS messages are intercepted, the contents may be retrieved. When arbitrary FINS messages are injected, any commands may be executed on, or the system information may be retrieved from, the affected device. Affected products and versions are as follows: SYSMAC CS-series CPU Units, all versions, SYSMAC CJ-series CPU Units, all versions, SYSMAC CP-series CPU Units, all versions, SYSMAC NJ-series CPU Units, all versions, SYSMAC NX1P-series CPU Units, all versions, SYSMAC NX102-series CPU Units, all versions, and SYSMAC NX7 Database Connection CPU Units (Ver.1.16 or later)

Severity
Critical
CVSS
9.8 (3.1)
Published
2023-06-19
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-306

Affected products

  • omron / cs1w-eip21_firmware
  • omron / cs1w-spu01-v2_firmware
  • omron / cs1w-spu02-v2_firmware
  • omron / cs1w-etn21_firmware
  • omron / cs1w-clk_firmware
  • omron / cs1w-fln22_firmware

Showing 6 representative product identities from 317 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

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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