CVE-2025-53558
📋 TL;DR
ZTE Japan's ZXHN-F660T and ZXHN-F660A routers use a hardcoded credential shared across all installations, allowing attackers with knowledge of this credential to authenticate to affected devices. This affects all users of these specific router models in Japan. The vulnerability enables unauthorized access to router administration interfaces.
💻 Affected Systems
- ZXHN-F660T
- ZXHN-F660A
⚠️ 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
Complete compromise of router configuration, enabling traffic interception, network redirection, credential theft, and persistent backdoor installation across the entire network.
Likely Case
Unauthorized access to router admin panel leading to network configuration changes, DNS hijacking, and potential credential harvesting from connected devices.
If Mitigated
Limited impact if devices are behind firewalls with strict access controls and network segmentation prevents lateral movement.
🎯 Exploit Status
Exploitation requires knowledge of the hardcoded credential but is trivial once obtained. No authentication bypass needed beyond credential knowledge.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check with ZTE Japan for specific firmware versions
Vendor Advisory: https://jvn.jp/en/jp/JVN66546573/
Restart Required: Yes
Instructions:
1. Contact ZTE Japan for updated firmware. 2. Download firmware from official ZTE Japan portal. 3. Access router admin panel. 4. Navigate to firmware update section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Change Admin Credentials
allChange default admin password to unique strong credentials
Access router admin panel and navigate to password/security settings
Restrict Management Access
allLimit admin interface access to specific IP addresses or VLANs
Configure firewall rules to restrict access to router management IP/ports
🧯 If You Can't Patch
- Isolate affected routers in separate network segments with strict firewall rules
- Implement network monitoring for unauthorized access attempts to router management interfaces
🔍 How to Verify
Check if Vulnerable:
Attempt to authenticate to router admin interface using known default/hardcoded credentialsCheck Version:
Check router admin panel system information or use telnet/ssh to query firmware versionVerify Fix Applied:
Verify authentication fails with old credentials and new firmware version is installed📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts followed by successful login
- Multiple login attempts from unusual IP addresses
- Configuration changes from unauthorized users
Network Indicators:
- Unusual traffic patterns from router management interface
- DNS configuration changes
- Port scanning from router IP
SIEM Query:
source="router_logs" AND (event_type="authentication" AND result="success") AND user="admin"