OfficeApplication · Cybozu

CVE-2021-20624

MEDIUM · 6.5 CVSS v3.1 Published 2021-03-18
Fix available
A fix is available. Upgrade to after 10.8.4 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Improper access control vulnerability in Cybozu Office's Scheduler component (versions 10.0.0-10.8.4) allows authenticated attackers to bypass access restrictions and modify Scheduler data due to insufficient authorization checks in unspecified entry points.

MitigationUpgrade to Cybozu Office version 10.8.5 or later which contains the patched access control mechanisms; review Scheduler permission models and implement additional authorization validation as a defense-in-depth measure.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
OfficeApplication
Affected:>= 10.0.0, <= 10.8.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Cybozu Office installation
    Locate Cybozu Office installation directory or identify running Cybozu processes on the system
    Affected if Cybozu Office is not installed on the system
  2. Identify installed Cybozu Office version
    Access the Cybozu Office administrator settings page or check version information file in the installation directory
    Affected if Version cannot be determined or is within 10.0.0 to 10.8.4 inclusive
  3. Verify Scheduler component is enabled
    Log into Cybozu Office as an administrator and navigate to the system settings or application management section to confirm the Scheduler module is active
    Affected if Scheduler component is enabled and in use
  4. Confirm user authentication is possible
    Verify that user authentication mechanisms are configured and functional in Cybozu Office
    Affected if Authenticated users exist who could potentially access the Scheduler

The environment is affected if Cybozu Office version 10.0.0 through 10.8.4 is installed with the Scheduler component enabled, as authenticated attackers could exploit improper authorization checks to modify Scheduler data.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 10.8.4
Interim mitigation

Upgrade to Cybozu Office version 10.8.5 or later which contains the patched access control mechanisms; review Scheduler permission models and implement additional authorization validation as a defense-in-depth measure.

Fix this in Office Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA3.0 h
16.0 hours of engineering $2,820
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,512.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-20624 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-20624 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data