CVE intelligence and bounded remediation

CVE-2020-16850 — Mitsubishielectric R00Cpu Firmware security vulnerability

High CVSS 7.8

Mitsubishi MELSEC iQ-R Series PLCs with firmware 49 allow an unauthenticated attacker to halt the industrial process by sending a crafted packet over the network. This denial of service attack exposes Improper Input Validation. After halting, physical access to the PLC is required in order to restore production, and the device state is lost. This is related to R04CPU, RJ71GF11-T2, R04CPU, and RJ71GF11-T2.

Severity
High
CVSS
7.8 (2.0)
Published
2020-11-30
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-20, CWE-400

Affected products

  • mitsubishielectric / r00cpu_firmware
  • mitsubishielectric / r01cpu_firmware
  • mitsubishielectric / r02cpu_firmware
  • mitsubishielectric / r04cpu_firmware
  • mitsubishielectric / r08cpu_firmware
  • mitsubishielectric / r16cpu_firmware

Showing 6 representative product identities from 19 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

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

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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