What is CVE-2021-20624?

CVE-2021-20624 is a medium-severity vulnerability in Cybozu Office. CVSS score: 6.5/10. Published 2021-03-18.

How severe is CVE-2021-20624?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Cybozu Office

CVE-2021-20624

Improper access control vulnerability in Scheduler of Cybozu Office 10.0.0 to 10.8.4 allows an authenticated attacker to bypass access restriction and alter the data of Scheduler via unspecified vectors.

Published 2021-03-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.008 (54.1th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 54.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Cybozu Office
Cybozu, Inc. Cybozu Office — versions 10.0.0 to 10.8.4

References

kb.cybozu.support/article/36866/ (Vendor Advisory)
jvn.jp/en/jp/JVN45797538/index.html (Third Party Advisory)

Frequently asked questions

What is CVE-2021-20624?: CVE-2021-20624 is a medium-severity vulnerability in Cybozu Office. CVSS score: 6.5/10. Published 2021-03-18.
How severe is CVE-2021-20624?: Medium severity. CVSS v3 base score is 6.5 out of 10.