How severe is CVE-2021-20634?

CVE-2021-20634 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-20634 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20634?

CVE-2021-20634 affects Cybozu Office. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20634?

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

When was CVE-2021-20634 published?

CVE-2021-20634 was published on 2021-03-18 and last updated on 2026-06-17.

CVE-2021-20634

CVE-2021-20634 is a medium-severity vulnerability in Cybozu Office with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 4.0
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Cybozu Office
Published: 2021-03-18
Last modified: 2026-06-17

Description

Improper access control vulnerability in Custom App of Cybozu Office 10.0.0 to 10.8.4 allows authenticated attackers to bypass access restriction and obtain the date of Custom App via unspecified vectors.

Frequently asked questions

What is CVE-2021-20634?: Improper access control vulnerability in Custom App of Cybozu Office 10.0.0 to 10.8.4 allows authenticated attackers to bypass access restriction and obtain the date of Custom App via unspecified vectors.
How severe is CVE-2021-20634?: CVE-2021-20634 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-20634 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20634?: CVE-2021-20634 affects Cybozu Office. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20634?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20634 published?: CVE-2021-20634 was published on 2021-03-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:cybozu:office:*:*:*:*:*:*:*:*

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