CVE intelligence and bounded remediation

CVE-2020-5527 — Mitsubishielectric Cr800-Q Firmware security vulnerability

High CVSS 7.5

When MELSOFT transmission port (UDP/IP) of Mitsubishi Electric MELSEC iQ-R series (all versions), MELSEC iQ-F series (all versions), MELSEC Q series (all versions), MELSEC L series (all versions), and MELSEC F series (all versions) receives massive amount of data via unspecified vectors, resource consumption occurs and the port does not process the data properly. As a result, it may fall into a denial-of-service (DoS) condition. The vendor states this vulnerability only affects Ethernet communication functions.

Severity
High
CVSS
7.5 (3.1)
Published
2020-03-30
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-400

Affected products

  • mitsubishielectric / cr800-q_firmware
  • mitsubishielectric / fx3g_firmware
  • mitsubishielectric / fx3gc_firmware
  • mitsubishielectric / fx3s_firmware
  • mitsubishielectric / fx3u_firmware
  • mitsubishielectric / fx3uc_firmware

Showing 6 representative product identities from 46 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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