Vulnerability Monitor

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CVE-2021-20591


Uncontrolled Resource Consumption vulnerability in Mitsubishi Electric MELSEC iQ-R series CPU modules (R00/01/02CPU all versions, R04/08/16/32/120(EN)CPU all versions, R08/16/32/120SFCPU all versions, R08/16/32/120PCPU all versions, R08/16/32/120PSFCPU all versions) allows a remote unauthenticated attacker to prevent legitimate clients from connecting to the MELSOFT transmission port (TCP/IP) by not closing a connection properly, which may lead to a denial of service (DoS) condition.


Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 40 products from mitsubishielectric, from mitsubishielectric, from mitsubishielectric and 37 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2021-06-11T16:15:08.987

Last Modified

2024-11-21T05:46:50.187

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.5 (HIGH)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:N/I:N/A:C

  • Access Vector: NETWORK
  • Access Complexity: LOW
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: COMPLETE
Exploitability Score

10.0

Impact Score

6.9

Weaknesses
  • Type: Primary
    CWE-400

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Operating System mitsubishielectric r00cpu_firmware * Yes
Hardware mitsubishielectric r00cpu - No
Operating System mitsubishielectric r01cpu_firmware * Yes
Hardware mitsubishielectric r01cpu - No
Operating System mitsubishielectric r02cpu_firmware * Yes
Hardware mitsubishielectric r02cpu - No
Operating System mitsubishielectric r04cpu_firmware * Yes
Hardware mitsubishielectric r04cpu - No
Operating System mitsubishielectric r08cpu_firmware * Yes
Hardware mitsubishielectric r08cpu - No
Operating System mitsubishielectric r16cpu_firmware * Yes
Hardware mitsubishielectric r16cpu - No
Operating System mitsubishielectric r32cpu_firmware * Yes
Hardware mitsubishielectric r32cpu - No
Operating System mitsubishielectric r120cpu_firmware * Yes
Hardware mitsubishielectric r120cpu - No
Operating System mitsubishielectric r08sfcpu_firmware * Yes
Hardware mitsubishielectric r08sfcpu - No
Operating System mitsubishielectric r16sfcpu_firmware * Yes
Hardware mitsubishielectric r16sfcpu - No
Operating System mitsubishielectric r32sfcpu_firmware * Yes
Hardware mitsubishielectric r32sfcpu - No
Operating System mitsubishielectric r120sfcpu_firmware * Yes
Hardware mitsubishielectric r120sfcpu - No
Operating System mitsubishielectric r08pcpu_firmware * Yes
Hardware mitsubishielectric r08pcpu - No
Operating System mitsubishielectric r16pcpu_firmware * Yes
Hardware mitsubishielectric r16pcpu - No
Operating System mitsubishielectric r32pcpu_firmware * Yes
Hardware mitsubishielectric r32pcpu - No
Operating System mitsubishielectric r120pcpu_firmware * Yes
Hardware mitsubishielectric r120pcpu - No
Operating System mitsubishielectric r08psfcpu_firmware * Yes
Hardware mitsubishielectric r08psfcpu - No
Operating System mitsubishielectric r16psfcpu_firmware * Yes
Hardware mitsubishielectric r16psfcpu - No
Operating System mitsubishielectric r32psfcpu_firmware * Yes
Hardware mitsubishielectric r32psfcpu - No
Operating System mitsubishielectric r120psfcpu_firmware * Yes
Hardware mitsubishielectric r120psfcpu - No

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For mitsubishielectric's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.