Security readout for executives and security teams
Plain-English summary
Cybozu Garoon versions 4.0.0 through 5.0.2 have an E-mail input validation flaw. A remote attacker who already has administrative privilege could change E-mail data without the appropriate privilege. This is mainly an integrity and internal-admin-abuse risk, not a publicly sourced unauthenticated compromise scenario.
Executive priority
Treat this as a targeted integrity risk for affected Garoon environments. Prioritize version inventory, admin access review, and vendor-guided remediation, particularly where Garoon supports sensitive internal communications.
Technical view
The CVE describes improper input validation in the E-mail component of Cybozu Garoon 4.0.0 to 5.0.2. The stated attacker model is remote with administrative privilege, enabling unauthorized alteration of E-mail data. No CVSS vector, CWE, exploit details, or explicit remediation text is included in the provided bundle.
Likely exposure
Organizations running Cybozu Garoon 4.0.0 to 5.0.2, especially deployments where administrative access is reachable beyond tightly trusted networks or roles.
Exploitation context
The bundle does not show CISA KEV listing or active exploitation evidence. Exploitation is described as requiring administrative privilege, so the practical risk centers on compromised, overprivileged, or misused admin accounts.
Researcher notes
The source bundle is sparse: no CVSS, CWE, proof-of-concept status, or detailed patch instructions are provided. Do not assume broader product impact beyond Cybozu Garoon 4.0.0 to 5.0.2 or unauthenticated exploitation.
Mitigation direction
- Inventory Cybozu Garoon deployments and identify versions 4.0.0 through 5.0.2.
- Review Cybozu and JVN advisories for supported fixes or vendor-approved workarounds.
- Limit Garoon administrative access to trusted administrators and trusted network paths.
- Review administrative role assignments for excessive access to E-mail functions.
- Monitor for unexpected E-mail data changes by administrative accounts.
Validation and detection
- Confirm the installed Garoon version on each deployment.
- Check whether the E-mail component is enabled or operationally used.
- Review admin account inventory and recent privilege changes.
- Audit E-mail data modification logs for unexpected administrative activity.
- Track remediation status against Cybozu and JVN advisory guidance.
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-2021-20761 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.