CVE-2024-47265
📋 TL;DR
This CVE describes a path traversal vulnerability in Synology Active Backup for Business that allows remote authenticated users to write specific files via the encrypted share umount functionality. It affects users running vulnerable versions of the software, potentially enabling unauthorized file writes on the system. The vulnerability is mitigated by updating to patched versions.
💻 Affected Systems
- Synology Active Backup for Business
📦 What is this software?
Active Backup For Business Agent by Synology
Active Backup For Business Agent by Synology
⚠️ Risk & Real-World Impact
Worst Case
An attacker could write arbitrary files to sensitive system locations, leading to data corruption, privilege escalation, or denial of service by overwriting critical files.
Likely Case
Authenticated users may exploit this to write specific files, potentially causing data integrity issues or limited system disruption, but full arbitrary file write is not confirmed.
If Mitigated
With proper access controls and network segmentation, impact is limited to isolated file writes within the application's context, reducing broader system compromise.
🎯 Exploit Status
Exploitation requires authenticated access and specific vectors are unspecified, making it moderately complex to execute without detailed knowledge.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.7.1-13234, 2.7.1-23234, or 2.7.1-3234 (depending on product variant)
Vendor Advisory: https://www.synology.com/en-global/security/advisory/Synology_SA_25_02
Restart Required: Yes
Instructions:
1. Log into Synology DSM. 2. Open Package Center. 3. Find 'Active Backup for Business'. 4. Click 'Update' to install the latest version. 5. Restart the application or system as prompted.
🔧 Temporary Workarounds
Restrict Access to Active Backup
allLimit network access to Synology Active Backup for Business to trusted IPs or internal networks only.
Configure firewall rules to block external access to Active Backup ports (default varies; check documentation).
Disable Encrypted Shares if Unused
allTemporarily disable encrypted share functionality if not required, reducing attack surface.
In Active Backup settings, navigate to share management and disable encrypted shares.
🧯 If You Can't Patch
- Implement strict access controls to limit which users can authenticate to Active Backup, reducing potential attackers.
- Monitor logs for unusual file write activities related to encrypted share umount operations and set up alerts.
🔍 How to Verify
Check if Vulnerable:
Check the installed version of Active Backup for Business in Synology DSM Package Center; if it is before the patched versions, it is vulnerable.Check Version:
In DSM, run: synopkg version ActiveBackupBusiness or check via Package Center interface.Verify Fix Applied:
After updating, confirm the version in Package Center matches or exceeds 2.7.1-13234, 2.7.1-23234, or 2.7.1-3234.📡 Detection & Monitoring
Log Indicators:
- Unusual file write events in Active Backup logs, especially during encrypted share umount operations.
- Failed or successful authentication attempts followed by file modification activities.
Network Indicators:
- Suspicious network traffic to Active Backup ports from untrusted sources, particularly involving file transfer protocols.
SIEM Query:
Example: 'source="ActiveBackup" AND (event="file_write" OR event="umount") AND user!="trusted_user"'