Home/CVE/Improper access control vulnerability in Custom App of Cybozu Office 10.0.0 to 10.8.4 allows authenticated attackers to
CVE

CVE-2021-20634

Improper access control vulnerability in Custom App of Cybozu Office 10.0.0 to 10.8.4 allows authenticated attackers to

Improper access control vulnerability in Custom App of Cybozu Office 10.0.0 to 10.8.4 allows authenticated attackers to bypass access restriction and obtain the date of Custom App via unspecified vectors.

MEDIUM · CVSS 4.3 EPSS 0.00227
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules8 YARA rules0
▤

Affected Products & Versions

1
cybozu office>= 10.0.0 and <= 10.8.4
◈

Sigma Hunt Rules

8
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
producthighSuspicious Microsoft Office Child Process - MacOS
producthighCode Executed Via Office Add-in XLL File
producthighPotential Persistence Via Microsoft Office Add-In
producthighPotential Persistence Via Microsoft Office Startup Folder
producthighFile With Uncommon Extension Created By An Office Application
producthighOffice Macro File Creation From Suspicious Process
▣

Scoring & Timeline

4.3
MEDIUM · CVSS v3.1 · vultures@jpcert.or.jp
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD18 Mar 2021 · 01:15 AM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://jvn.jp/en/jp/JVN45797538/index.htmlThird Party Advisory
https://kb.cybozu.support/article/36865/Vendor Advisory
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