CVE intelligence and bounded remediation

CVE-2020-5652 — Mitsubishielectric Melsec Q-Q04Udpvcpu Firmware security vulnerability

High CVSS 7.5

Uncontrolled resource consumption vulnerability in Ethernet Port on MELSEC iQ-R, Q and L series CPU modules (R 00/01/02 CPU firmware versions '20' and earlier, R 04/08/16/32/120 (EN) CPU firmware versions '52' and earlier, R 08/16/32/120 SFCPU firmware versions '22' and earlier, R 08/16/32/120 PCPU all versions, R 08/16/32/120 PSFCPU all versions, R 16/32/64 MTCPU all versions, Q03 UDECPU, Q 04/06/10/13/20/26/50/100 UDEHCPU serial number '22081' and earlier , Q 03/04/06/13/26 UDVCPU serial number '22031' and earlier, Q 04/06/13/26 UDPVCPU serial number '22031' and earlier, Q 172/173 DCPU all versions, Q 172/173 DSCPU all versions, Q 170 MCPU all versions, Q 170 MSCPU all versions, L 02/06/26 CPU (-P) and L 26 CPU - (P) BT all versions) allows a remote unauthenticated attacker to stop the Ethernet communication functions of the products via a specially crafted packet, which may lead to a denial of service (DoS) condition .

Severity
High
CVSS
7.5 (3.1)
Published
2020-11-02
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-400

Affected products

  • mitsubishielectric / melsec_q-q04udpvcpu_firmware / 22031
  • mitsubishielectric / melsec_q-q06udpvcpu_firmware / 22031
  • mitsubishielectric / melsec_q-q13udpvcpu_firmware / 22031
  • mitsubishielectric / melsec_q-q26udpvcpu_firmware / 22031
  • mitsubishielectric / melsec_q-q03udvcpu_firmware / 22031
  • mitsubishielectric / melsec_q-q04udvcpu_firmware / 22031

Showing 6 representative product identities from 51 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

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