CVE-2025-62840
📋 TL;DR
This vulnerability in QNAP HBS 3 Hybrid Backup Sync allows error messages to expose sensitive application data. Attackers with local network access can exploit this to read potentially confidential information. All users running vulnerable versions of HBS 3 are affected.
💻 Affected Systems
- QNAP HBS 3 Hybrid Backup Sync
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Sensitive backup metadata, configuration details, or file information could be exposed, potentially enabling further attacks or data theft.
Likely Case
Limited exposure of application data that could reveal system information or backup structure, but not necessarily user files.
If Mitigated
With proper network segmentation and access controls, impact is limited to authorized users who already have network access.
🎯 Exploit Status
Exploitation requires local network access but no authentication to the application.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 26.2.0.938 and later
Vendor Advisory: https://www.qnap.com/en/security-advisory/qsa-25-46
Restart Required: Yes
Instructions:
1. Log into QNAP App Center. 2. Check for updates to HBS 3. 3. Update to version 26.2.0.938 or later. 4. Restart the HBS 3 service or the NAS device.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to HBS 3 service to only trusted hosts
Disable Unnecessary Services
allTurn off HBS 3 if not actively needed for backup operations
🧯 If You Can't Patch
- Implement strict network access controls to limit which devices can communicate with the HBS 3 service
- Monitor logs for unusual access patterns to HBS 3 endpoints
🔍 How to Verify
Check if Vulnerable:
Check HBS 3 version in QNAP App Center or via SSH: cat /etc/config/hbs3.conf | grep versionCheck Version:
cat /etc/config/hbs3.conf | grep versionVerify Fix Applied:
Confirm version is 26.2.0.938 or higher in App Center or configuration file📡 Detection & Monitoring
Log Indicators:
- Unusual error messages in HBS 3 logs
- Multiple failed requests to HBS 3 endpoints
Network Indicators:
- Unexpected network traffic to HBS 3 service ports from unauthorized hosts
SIEM Query:
source="hbs3.log" AND (error OR exception) AND sensitive