How severe is CVE-2021-20803?

CVE-2021-20803 has a CVSS 3.x base score of 5.4, 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 low, and availability low.

Is CVE-2021-20803 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20803?

CVE-2021-20803 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-2021-20803?

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

When was CVE-2021-20803 published?

CVE-2021-20803 was published on 2021-10-13 and last updated on 2026-06-17.

CVE-2021-20803

CVE-2021-20803 is a medium-severity vulnerability in Cybozu Remote Service Manager with a CVSS 3.x base score of 5.4. 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-863.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 4.0
EPSS exploit prediction: 1% (48th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Cybozu Remote Service Manager
Published: 2021-10-13
Last modified: 2026-06-17

Description

Operation restriction bypass in the management screen of Cybozu Remote Service 3.1.8 to 3.1.9 allows a remote authenticated attacker to alter the data of the management screen.

Frequently asked questions

What is CVE-2021-20803?: Operation restriction bypass in the management screen of Cybozu Remote Service 3.1.8 to 3.1.9 allows a remote authenticated attacker to alter the data of the management screen.
How severe is CVE-2021-20803?: CVE-2021-20803 has a CVSS 3.x base score of 5.4, 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 low, and availability low.
Is CVE-2021-20803 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20803?: CVE-2021-20803 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-2021-20803?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20803 published?: CVE-2021-20803 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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