Security readout for executives and security teams
Plain-English summary
Cybozu Garoon versions 4.0.0 through 5.5.0 have a cross-site scripting issue in some E-mail functions. An authenticated remote user could inject script that runs in another user's browser. Business risk depends on who can access Garoon and how broadly E-mail functions are used.
Executive priority
Treat this as a near-term remediation item for affected Garoon environments, not an emergency based on current evidence. Prioritize systems with broad user access or external reachability.
Technical view
CVE-2021-20774 is an authenticated XSS vulnerability in unspecified Cybozu Garoon E-mail functions affecting versions 4.0.0 to 5.5.0. The provided sources do not include CVSS, CWE, exact vectors, proof of exploitation, or a specific fixed version.
Likely exposure
Organizations using Cybozu Garoon 4.0.0 through 5.5.0 are potentially exposed, especially where many internal users can access E-mail functions. Exposure is lower where Garoon access is tightly limited and accounts are strongly controlled.
Exploitation context
The CVE states exploitation requires a remote authenticated attacker. The source bundle does not show CISA KEV listing, active exploitation, public exploit availability, or technical attack details.
Researcher notes
Key gaps remain: no CVSS, no precise affected functions, no vectors, and no source-confirmed fix version in the provided bundle. Validation should avoid exploit reproduction and focus on version, feature exposure, and vendor advisory confirmation.
Mitigation direction
- Inventory Cybozu Garoon deployments and confirm installed versions.
- Review Cybozu and JVN guidance for the vendor-approved fix or workaround.
- Restrict Garoon access to trusted users and networks where operationally feasible.
- Monitor Garoon accounts for suspicious authenticated activity.
- Prioritize remediation for internet-accessible or broadly used Garoon instances.
Validation and detection
- Check whether any Garoon instance runs version 4.0.0 through 5.5.0.
- Confirm whether E-mail functions are enabled and used by ordinary users.
- Review access logs for unusual authenticated Garoon activity.
- Verify vendor advisory status before declaring remediation complete.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-20774 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://cs.cybozu.co.jp/2021/007206.htmlCVE reference · x_refsource_MISC
- https://jvn.jp/en/jp/JVN54794245/index.htmlCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.