CVE-2021-20609

HIGH
7.5
CVSS Score
Published: December 1, 2021 at 03:41 PM UTC
Updated: June 17, 2026 at 03:34 AM UTC
121 products affected across 1 vendorMELIPC MI5122-VWMELSEC Iq R R120 CPU FirmwareMELSEC Iq R R04 CPU Firmware· also runs on 55 platforms

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Severity
HIGH7.5
Exploit prediction
EPSS 3%

Description

Uncontrolled Resource Consumption vulnerability in Mitsubishi Electric MELSEC iQ-R Series R00/01/02CPU, MELSEC iQ-R Series R04/08/16/32/120(EN)CPU, MELSEC iQ-R Series R08/16/32/120SFCPU, MELSEC iQ-R Series R08/16/32/120PCPU, MELSEC iQ-R Series R08/16/32/120PSFCPU, MELSEC iQ-R Series R16/32/64MTCPU, MELSEC iQ-R Series R12CCPU-V, MELSEC Q Series Q03UDECPU, MELSEC Q Series Q04/06/10/13/20/26/50/100UDEHCPU, MELSEC Q Series Q03/04/06/13/26UDVCPU, MELSEC Q Series Q04/06/13/26UDPVCPU, MELSEC Q Series Q12DCCPU-V, MELSEC Q Series Q24DHCCPU-V(G), MELSEC Q Series Q24/26DHCCPU-LS, MELSEC Q Series MR-MQ100, MELSEC Q Series Q172/173DCPU-S1, MELSEC Q Series Q172/173DSCPU, MELSEC Q Series Q170MCPU, MELSEC Q Series Q170MSCPU(-S1), MELSEC L Series L02/06/26CPU(-P), MELSEC L Series L26CPU-(P)BT and MELIPC Series MI5122-VW allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition by sending specially crafted packets. System reset is required for recovery.

Affected

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

v ≤ 24
mitsubishi-melsec-iq-r-r00-cpu (environment)
v ≤ 24
mitsubishi-melsec-iq-r-r01-cpu (environment)
v ≤ 24
mitsubishi-melsec-iq-r-r02-cpu (environment)
v ≤ 57
mitsubishi-melsec-iq-r-r04-cpu (environment)
v ≤ 29
mitsubishi-melsec-iq-r-r04-pcpu (environment)
v ≤ 57
mitsubishi-melsec-iq-r-r08-cpu (environment)
v ≤ 29
mitsubishi-melsec-iq-r-r08-pcpu (environment)
All versions
mitsubishi-melsec-iq-r-r08-sfcpu (environment)
All versions
mitsubishi-melsec-iq-r-r12-ccpu-v (environment)

Remediation

No guide yet

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

CVSS

7.5HIGHMitsubishi
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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