CVE-2024-21902
📋 TL;DR
This CVE describes an incorrect permission assignment vulnerability in QNAP operating systems that allows authenticated users to read or modify critical resources via network access. The vulnerability affects multiple QNAP OS versions and could lead to unauthorized data access or system modification. Organizations using affected QNAP devices are at risk.
💻 Affected Systems
- QNAP QTS
- QNAP QuTS hero
📦 What is this software?
Qts by Qnap
Qts by Qnap
Qts by Qnap
Qts by Qnap
Qts by Qnap
Qts by Qnap
Qts by Qnap
Qts by Qnap
Qts by Qnap
Qts by Qnap
Qts by Qnap
Qts by Qnap
⚠️ Risk & Real-World Impact
Worst Case
Authenticated attackers could gain unauthorized access to sensitive system files, modify critical configurations, or potentially escalate privileges to compromise the entire QNAP system.
Likely Case
Authenticated users (including low-privileged accounts) could access sensitive data they shouldn't have permission to view, potentially exposing confidential information or system configurations.
If Mitigated
With proper network segmentation and strict access controls, the impact would be limited to authorized users within the network segment, reducing exposure of sensitive resources.
🎯 Exploit Status
Exploitation requires authenticated access but the vulnerability itself is straightforward - incorrect permissions on critical resources.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: QTS 5.1.7.2770 build 20240520 and later, QuTS hero h5.1.7.2770 build 20240520 and later
Vendor Advisory: https://www.qnap.com/en/security-advisory/qsa-24-23
Restart Required: Yes
Instructions:
1. Log into QNAP device admin interface. 2. Navigate to Control Panel > System > Firmware Update. 3. Check for updates and install QTS 5.1.7.2770 or QuTS hero h5.1.7.2770. 4. Reboot the device after installation completes.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to QNAP devices to only trusted internal networks
Access Control Hardening
allReview and restrict user permissions, disable unnecessary accounts, implement principle of least privilege
🧯 If You Can't Patch
- Implement strict network access controls to limit which users can reach QNAP devices
- Regularly audit user accounts and permissions, removing unnecessary access rights
🔍 How to Verify
Check if Vulnerable:
Check QNAP system version in Control Panel > System > Firmware Update. If version is earlier than QTS 5.1.7.2770 or QuTS hero h5.1.7.2770, the system is vulnerable.Check Version:
ssh admin@qnap-ip 'cat /etc/config/uLinux.conf | grep Version'Verify Fix Applied:
After updating, verify the version shows QTS 5.1.7.2770 or QuTS hero h5.1.7.2770 or later in Control Panel > System > Firmware Update.📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns by authenticated users
- Permission modification events in system logs
- Access to sensitive system files by non-admin users
Network Indicators:
- Unusual network traffic to QNAP device from authenticated user accounts
- Multiple failed permission requests followed by successful access
SIEM Query:
source="qnap_logs" AND (event_type="file_access" OR event_type="permission_change") AND user!="admin" AND resource="system_file*"