How severe is CVE-2021-20802?

CVE-2021-20802 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-20802 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20802?

CVE-2021-20802 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-2021-20802?

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

When was CVE-2021-20802 published?

CVE-2021-20802 was published on 2021-10-13 and last updated on 2026-06-17.

CVE-2021-20802

CVE-2021-20802 is a medium-severity vulnerability in Cybozu Remote Service Manager with a CVSS 3.x base score of 5.3. 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-74.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-74
Affected product: Cybozu Remote Service Manager
Published: 2021-10-13
Last modified: 2026-06-17

Description

HTTP header injection vulnerability in Cybozu Remote Service 3.1.8 to 3.1.9 allows a remote attacker to alter the information stored in the product.

Frequently asked questions

What is CVE-2021-20802?: HTTP header injection vulnerability in Cybozu Remote Service 3.1.8 to 3.1.9 allows a remote attacker to alter the information stored in the product.
How severe is CVE-2021-20802?: CVE-2021-20802 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-20802 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20802?: CVE-2021-20802 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-2021-20802?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20802 published?: CVE-2021-20802 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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