CVE-2021-20770
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 · uneditedCross-site scripting vulnerability in Message of Cybozu Garoon 4.6.0 to 5.0.2 allows a remote authenticated attacker to inject an arbitrary script 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 confidenceCross-site scripting (XSS) vulnerability in the Message component of Cybozu Garoon versions 4.6.0 through 5.0.2 allows an authenticated remote attacker to inject and execute arbitrary JavaScript scripts via unspecified vectors.
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>= 4.6.0, <= 5.0.2CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify Cybozu Garoon installation versionAccess the Garoon system administration panel or check the product version information, typically found in the 'System Settings > System Information' or by examining the garoon.ini/config fileAffected if The installed version is 4.6.0, 4.6.1, 4.6.2, 4.10.0, 5.0.0, 5.0.1, or 5.0.2 (any version from 4.6.0 through 5.0.2)
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Confirm version is within affected rangeCompare the identified version against the affected range: 4.6.0 <= version <= 5.0.2Affected if The version falls within or overlaps the range 4.6.0 to 5.0.2
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Verify Message component is accessibleLog into Garoon as an authenticated user and navigate to the Message module (Messaging/Communication section)Affected if The Message component is enabled and accessible to users
If Cybozu Garoon version 4.6.0 through 5.0.2 is installed AND the Message module is in use, the environment is affected by this XSS vulnerability.
Generated from the published advisory. Verify against your own configuration.
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.
dbcve · scopedUpgrade to Cybozu Garoon version 5.0.3 or later. Apply output encoding and input validation to all user-supplied data in the Message module.
Garoon 5.0.3 or later (latest 5.x release)
- 1. Back up the current Garoon installation and database before proceeding with any upgrade.
- 2. Download the latest version of Cybozu Garoon from the official vendor website or your licensed download channel.
- 3. Review the vendor's upgrade documentation for Garoon 5.x to understand the upgrade process.
- 4. Execute the upgrade following the vendor's recommended upgrade path (typically from your current version to the latest 5.x release).
- 5. After upgrade, verify that the Message function is working correctly and test that XSS filtering is functioning as expected.
- 6. Confirm the fixed version is installed by checking the Garoon version information.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20770 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-20770 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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