CVE-2025-30485
📋 TL;DR
A UNIX symbolic link following vulnerability in FutureNet NXR, VXR, and WXR series routers allows logged-in administrative users to access or destroy internal files by connecting external storage containing malicious symlinks. This affects administrative users with physical or network access to these routers. The vulnerability enables privilege escalation within the router's file system.
💻 Affected Systems
- FutureNet NXR series routers
- FutureNet VXR series routers
- FutureNet WXR series routers
⚠️ 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
Administrative user could delete critical system files, modify configurations, or extract sensitive data, potentially causing router failure or persistent backdoor installation.
Likely Case
Privileged user could read sensitive configuration files, modify network settings, or disrupt router functionality by deleting key files.
If Mitigated
With proper access controls and monitoring, impact is limited to file system manipulation within the router's internal storage.
🎯 Exploit Status
Exploitation requires administrative credentials and physical/network access to mount external storage
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific firmware versions
Vendor Advisory: https://www.centurysys.co.jp/backnumber/common/jvnvu92821536.html
Restart Required: Yes
Instructions:
1. Check vendor advisory for patched firmware version. 2. Download firmware from vendor portal. 3. Backup current configuration. 4. Upload and apply firmware update through web interface. 5. Reboot router. 6. Verify firmware version.
🔧 Temporary Workarounds
Disable external storage mounting
allPrevent mounting of USB/external storage devices on affected routers
Check router web interface for USB/storage settings and disable
Restrict administrative access
allLimit administrative user accounts and implement strong authentication
Configure router to require strong passwords and limit admin accounts
🧯 If You Can't Patch
- Implement strict access controls to router management interfaces
- Monitor for unauthorized external storage connections and file system changes
🔍 How to Verify
Check if Vulnerable:
Check router firmware version against vendor advisory. If running unpatched firmware with external storage capability, assume vulnerable.Check Version:
Check router web interface or CLI for firmware version informationVerify Fix Applied:
Verify firmware version matches patched version from vendor advisory. Test external storage mounting with symlinks to confirm proper handling.📡 Detection & Monitoring
Log Indicators:
- External storage mount events
- File system access to sensitive paths
- Configuration file modifications
Network Indicators:
- Unauthorized administrative login attempts
- Unusual configuration changes
SIEM Query:
Search for router logs containing 'mount', 'USB', 'storage', or file access to system directories by admin users