CVE intelligence and bounded remediation

CVE-2021-20599 — Mitsubishielectric R08Sfcpu Firmware security vulnerability

Critical CVSS 9.1

Cleartext Transmission of Sensitive InformationCleartext transmission of sensitive information vulnerability in MELSEC iQ-R series Safety CPU R08/16/32/120SFCPU firmware versions "26" and prior and MELSEC iQ-R series SIL2 Process CPU R08/16/32/120PSFCPU firmware versions "11" and prior allows a remote unauthenticated attacker to login to a target CPU module by obtaining credentials other than password.

Severity
Critical
CVSS
9.1 (3.1)
Published
2021-10-14
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-319, CWE-639

Affected products

  • mitsubishielectric / r08sfcpu_firmware
  • mitsubishielectric / r16sfcpu_firmware
  • mitsubishielectric / r32sfcpu_firmware
  • mitsubishielectric / r120sfcpu_firmware
  • mitsubishielectric / r08psfcpu_firmware
  • mitsubishielectric / r16psfcpu_firmware

Showing 6 representative product identities from 8 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Authorization bypass, IDOR, and cross-tenant access

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

Check exposure

  • Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
  • Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
  • Use synthetic fixtures to compare intended access matrices without accessing another user's real data.

Remediate safely

  • Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
  • Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
  • Add deny-by-default policy tests for horizontal and vertical access across every affected transport.

Authoritative sources

Complete CVE record and remediation plan

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