How severe is CVE-2021-20600?

CVE-2021-20600 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-20600 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20600?

CVE-2021-20600 affects Mitsubishielectric R12ccpu-v Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20600?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-20600 published?

CVE-2021-20600 was published on 2021-10-08 and last updated on 2026-06-17.

CVE-2021-20600

CVE-2021-20600 is a medium-severity vulnerability in Mitsubishielectric R12ccpu-v Firmware with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 7.1
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Mitsubishielectric R12ccpu-v Firmware
Published: 2021-10-08
Last modified: 2026-06-17

Description

Uncontrolled resource consumption in Mitsubishi Electric MELSEC iQ-R series C Controller Module R12CCPU-V Firmware Versions "16" and prior allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition by sending a large number of packets in a short time while the module starting up. System reset is required for recovery.

Frequently asked questions

What is CVE-2021-20600?: Uncontrolled resource consumption in Mitsubishi Electric MELSEC iQ-R series C Controller Module R12CCPU-V Firmware Versions "16" and prior allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition by sending a large number of packets in a short time while the module starting up. System reset is required for recovery.
How severe is CVE-2021-20600?: CVE-2021-20600 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-20600 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20600?: CVE-2021-20600 affects Mitsubishielectric R12ccpu-v Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20600?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20600 published?: CVE-2021-20600 was published on 2021-10-08 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:mitsubishielectric:r12ccpu-v_firmware:*:*:*:*:*:*:*:*

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