CVE-2021-20591

HIGH
7.5
CVSS Score
Published: June 11, 2021 at 03:52 PM UTC
Updated: June 17, 2026 at 03:34 AM UTC
41 products affected across 1 vendorR120SFCPU FirmwareR08SFCPU FirmwareR32SFCPU Firmware

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Severity
HIGH7.5
Exploit prediction
EPSS 1%

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions
mitsubishielectric-r00cpu (same device)
All versions
mitsubishielectric-r01cpu (same device)
All versions
mitsubishielectric-r02cpu (same device)
All versions
mitsubishielectric-r04cpu (same device)
All versions
mitsubishielectric-r08cpu (same device)
All versions
mitsubishielectric-r08pcpu (same device)
All versions
mitsubishielectric-r08psfcpu (same device)
All versions
mitsubishielectric-r08sfcpu (same device)
All versions
mitsubishielectric-r120cpu (same device)
All versions
mitsubishielectric-r120pcpu (same device)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-400

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