How severe is CVE-2021-40333?

CVE-2021-40333 has a CVSS 3.x base score of 9.0, rated critical severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability high.

Is CVE-2021-40333 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-40333?

CVE-2021-40333 primarily affects Hitachienergy Fox615 Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-40333?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-40333 published?

CVE-2021-40333 was published on 2021-12-02 and last updated on 2026-06-17.

CVE-2021-40333

CVE-2021-40333 is a critical-severity vulnerability in Hitachienergy Fox615 Firmware with a CVSS 3.x base score of 9.0. 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-521.

Key facts

Severity: Critical (CVSS 3.x base score 9.0)
CVSS v2: 5.5
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-521
Affected product: Hitachienergy Fox615 Firmware
Published: 2021-12-02
Last modified: 2026-06-17

Description

Weak Password Requirements vulnerability in Hitachi Energy FOX61x, XCM20 allows an attacker to gain unauthorized access to the Data Communication Network (DCN) routing configuration. This issue affects: Hitachi Energy FOX61x versions prior to R15A. Hitachi Energy XCM20 versions prior to R15A.

Frequently asked questions

What is CVE-2021-40333?: Weak Password Requirements vulnerability in Hitachi Energy FOX61x, XCM20 allows an attacker to gain unauthorized access to the Data Communication Network (DCN) routing configuration. This issue affects: Hitachi Energy FOX61x versions prior to R15A. Hitachi Energy XCM20 versions prior to R15A.
How severe is CVE-2021-40333?: CVE-2021-40333 has a CVSS 3.x base score of 9.0, rated critical severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability high.
Is CVE-2021-40333 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40333?: CVE-2021-40333 primarily affects Hitachienergy Fox615 Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-40333?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-40333 published?: CVE-2021-40333 was published on 2021-12-02 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:o:hitachienergy:fox615_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:xcm20_firmware:*:*:*:*:*:*:*:*

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