CVE-2025-53939
📋 TL;DR
CVE-2025-53939 is an improper input validation vulnerability in Kiteworks private data network that allows attackers to elevate another user's permissions on shared folders. This affects all Kiteworks deployments prior to version 9.1.0. Attackers with access to the system could grant unauthorized access to sensitive shared data.
💻 Affected Systems
- Kiteworks Private Data Network
📦 What is this software?
Kiteworks by Accellion
⚠️ Risk & Real-World Impact
Worst Case
An authenticated attacker could elevate permissions for any user on any shared folder, potentially gaining unauthorized access to sensitive corporate data, intellectual property, or confidential information stored in the PDN.
Likely Case
An authenticated user with some access privileges could elevate permissions for themselves or others on specific shared folders, leading to unauthorized data access beyond their intended permissions.
If Mitigated
With proper access controls and monitoring, the impact is limited to unauthorized access to specific shared folders rather than system-wide compromise.
🎯 Exploit Status
Exploitation requires authenticated access to the Kiteworks system and knowledge of the role management functionality for shared folders.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 9.1.0
Vendor Advisory: https://github.com/kiteworks/security-advisories/security/advisories/GHSA-hpf5-6376-2565
Restart Required: Yes
Instructions:
1. Backup your Kiteworks configuration and data. 2. Download Kiteworks version 9.1.0 or later from the official vendor portal. 3. Follow the Kiteworks upgrade documentation for your deployment type (on-premises or cloud). 4. Apply the update and restart all Kiteworks services. 5. Verify the upgrade was successful.
🔧 Temporary Workarounds
Restrict Shared Folder Management
allTemporarily restrict access to shared folder role management functions to only essential administrators.
Enhanced Monitoring
allImplement additional logging and monitoring for shared folder permission changes.
🧯 If You Can't Patch
- Implement strict access controls and least privilege principles for all users with shared folder access
- Enable detailed audit logging for all shared folder permission changes and review logs regularly
🔍 How to Verify
Check if Vulnerable:
Check your Kiteworks version via the admin interface or by examining the system version files. If version is below 9.1.0, you are vulnerable.Check Version:
Check via Kiteworks admin console or examine /opt/kiteworks/version.txt on the serverVerify Fix Applied:
After upgrading, verify the version shows 9.1.0 or higher in the admin interface and test shared folder role management functionality.📡 Detection & Monitoring
Log Indicators:
- Unexpected role/permission changes on shared folders
- Multiple permission elevation attempts within short timeframes
- User accounts modifying permissions on folders they shouldn't have access to
Network Indicators:
- Unusual patterns of API calls to shared folder management endpoints
- Increased traffic to role management functions
SIEM Query:
source="kiteworks" AND (event_type="permission_change" OR event_type="role_modification") AND result="success" AND user NOT IN [admin_users]