CVE-2024-31398
📋 TL;DR
This vulnerability in Cybozu Garoon allows authenticated users to access sensitive user list information that should be restricted. It affects all users who can log into vulnerable versions of the software, potentially exposing organizational user data.
💻 Affected Systems
- Cybozu Garoon
📦 What is this software?
Garoon by Cybozu
⚠️ Risk & Real-World Impact
Worst Case
An authenticated attacker could enumerate all users in the system, potentially enabling targeted social engineering, credential attacks, or reconnaissance for further exploitation.
Likely Case
An authenticated user with legitimate access could inadvertently or intentionally view user lists beyond their intended permissions, violating privacy expectations.
If Mitigated
With proper access controls and monitoring, the impact is limited to information disclosure of user names/identifiers rather than more sensitive credentials.
🎯 Exploit Status
Exploitation requires valid user credentials; the vulnerability involves improper data handling in sent communications.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.15.3 or later
Vendor Advisory: https://cs.cybozu.co.jp/2024/007901.html
Restart Required: Yes
Instructions:
1. Download Garoon 5.15.3 or later from Cybozu support portal. 2. Backup current installation and database. 3. Apply the update following Cybozu's upgrade procedures. 4. Restart the Garoon service.
🔧 Temporary Workarounds
Restrict User Access
allTemporarily limit user accounts to only essential personnel while planning upgrade.
🧯 If You Can't Patch
- Implement strict access controls and monitor user activity for unusual enumeration attempts.
- Segment network access to Garoon instances and limit exposure to trusted users only.
🔍 How to Verify
Check if Vulnerable:
Check Garoon version in administration console or via system information page.Check Version:
Check via Garoon web interface: Administration > System InformationVerify Fix Applied:
Confirm version is 5.15.3 or later and test that user list access respects proper permissions.📡 Detection & Monitoring
Log Indicators:
- Unusual user enumeration patterns
- Multiple requests to user listing endpoints from single accounts
Network Indicators:
- Increased traffic to user directory APIs from non-admin accounts
SIEM Query:
source="garoon" AND (uri_path="/api/user/list" OR uri_path CONTAINS "user") AND user_role!="admin"