CVE-2025-26167
📋 TL;DR
CVE-2025-26167 is an arbitrary file read vulnerability in Buffalo LS520D NAS devices running firmware version 4.53. Unauthenticated attackers can exploit this to access the NAS web UI and read sensitive internal files. This affects all Buffalo LS520D NAS devices with the vulnerable firmware exposed to network access.
💻 Affected Systems
- Buffalo LS520D
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Attackers could read sensitive configuration files, credentials, or user data stored on the NAS, potentially leading to full system compromise or data exfiltration.
Likely Case
Unauthenticated attackers reading system files, configuration data, or potentially sensitive user information from the NAS.
If Mitigated
Limited impact if proper network segmentation and access controls prevent external access to the NAS web interface.
🎯 Exploit Status
The vulnerability allows unauthenticated access to read arbitrary files through the web UI interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Buffalo support for updated firmware
Vendor Advisory: https://www.buffalo.jp/support/download/
Restart Required: Yes
Instructions:
1. Log into Buffalo NAS web interface. 2. Navigate to System Settings > Firmware Update. 3. Check for and apply the latest firmware update. 4. Reboot the NAS after update completes.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to the NAS web interface using firewall rules
Disable Web UI Access
allTemporarily disable web UI access if not required for operations
🧯 If You Can't Patch
- Implement strict network access controls to limit NAS web UI access to trusted IPs only
- Monitor network traffic to the NAS web interface for suspicious file access patterns
🔍 How to Verify
Check if Vulnerable:
Check firmware version in NAS web interface under System Settings > Firmware InformationCheck Version:
Check via web UI: System Settings > Firmware InformationVerify Fix Applied:
Verify firmware version is updated beyond 4.53 in System Settings > Firmware Information📡 Detection & Monitoring
Log Indicators:
- Unauthenticated access attempts to web UI
- Unusual file read patterns in web server logs
Network Indicators:
- HTTP requests to NAS web interface from untrusted sources
- Patterns of file path traversal in HTTP requests
SIEM Query:
source="nas_web_logs" AND (status=200 AND (uri CONTAINS "../" OR uri CONTAINS "/etc/" OR uri CONTAINS "/config/"))