CVE intelligence and bounded remediation

CVE-2021-20597 — Mitsubishielectric R08Sfcpu Firmware security vulnerability

Critical CVSS 9.1

Insufficiently Protected Credentials vulnerability in Mitsubishi Electric MELSEC iQ-R series Safety CPU modules R08/16/32/120SFCPU firmware versions "26" and prior and Mitsubishi Electric MELSEC iQ-R series SIL2 Process CPU modules R08/16/32/120PSFCPU firmware versions "11" and prior allows a remote unauthenticated attacker to login to the target unauthorizedly by sniffing network traffic and obtaining credentials when registering user information in the target or changing a password.

Severity
Critical
CVSS
9.1 (3.1)
Published
2021-08-06
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-522

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

Information disclosure and sensitive data exposure

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

Check exposure

  • Trace sensitive data through responses, errors, logs, metrics, traces, caches, exports, files, backups, and client bundles.
  • Identify affected subjects, tenants, retention windows, access controls, and downstream copies without opening unnecessary sensitive records.
  • Review metadata, timing, status, length, and existence signals as well as direct content disclosure.

Remediate safely

  • Minimize collection and output, apply field-level authorization and redaction at a centralized boundary, and return generic external errors.
  • Remove secrets and sensitive data from logs, artifacts, URLs, caches, and client-side bundles; rotate credentials that may have been exposed.
  • Update the affected component and add synthetic-data tests for response, error, observability, and export paths.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.