How severe is CVE-2021-20804?

CVE-2021-20804 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-20804 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20804?

CVE-2021-20804 primarily affects Cybozu Remote Service Manager. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20804?

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

When was CVE-2021-20804 published?

CVE-2021-20804 was published on 2021-10-13 and last updated on 2026-06-17.

CVE-2021-20804

CVE-2021-20804 is a medium-severity vulnerability in Cybozu Remote Service Manager with a CVSS 3.x base score of 6.5. 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 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 1% (62nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Cybozu Remote Service Manager
Published: 2021-10-13
Last modified: 2026-06-17

Description

Cybozu Remote Service 3.1.8 to 3.1.9 allows a remote authenticated attacker to cause a denial of service (DoS) condition via unspecified vectors.

Frequently asked questions

What is CVE-2021-20804?: Cybozu Remote Service 3.1.8 to 3.1.9 allows a remote authenticated attacker to cause a denial of service (DoS) condition via unspecified vectors.
How severe is CVE-2021-20804?: CVE-2021-20804 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-20804 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20804?: CVE-2021-20804 primarily affects Cybozu Remote Service Manager. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20804?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20804 published?: CVE-2021-20804 was published on 2021-10-13 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:cybozu:remote_service_manager:3.1.8:*:*:*:*:*:*:*
cpe:2.3:a:cybozu:remote_service_manager:3.1.9:*:*:*:*:*:*:*

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