CVE-2018-10561
📋 TL;DR
This CVE describes an authentication bypass vulnerability in Dasan GPON home routers where attackers can access administrative interfaces by appending '?images' to URLs. This allows unauthorized management of affected routers, potentially impacting all users of vulnerable Dasan GPON router models.
💻 Affected Systems
- Dasan GPON home routers
📦 What is this software?
Gpon Router Firmware by Dasannetworks
⚠️ Risk & Real-World Impact
Worst Case
Complete router takeover allowing traffic interception, malware injection, network compromise, and persistent backdoor installation.
Likely Case
Unauthorized configuration changes, DNS hijacking, credential theft, and network monitoring.
If Mitigated
Limited impact if routers are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Simple HTTP request manipulation with publicly available exploit code.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Vendor-specific firmware updates
Vendor Advisory: No official vendor advisory found in provided references
Restart Required: Yes
Instructions:
1. Check Dasan website for firmware updates. 2. Download latest firmware. 3. Upload via router admin interface. 4. Reboot router.
🔧 Temporary Workarounds
Disable remote management
allDisable web management interface from WAN/Internet-facing interfaces
Network segmentation
allPlace routers in isolated network segments with strict firewall rules
🧯 If You Can't Patch
- Implement strict network access controls to limit router management interface exposure
- Monitor for unusual authentication attempts and configuration changes
🔍 How to Verify
Check if Vulnerable:
Attempt to access router admin page with ?images appended (e.g., http://router-ip/menu.html?images)Check Version:
Check router web interface or use vendor-specific CLI commandsVerify Fix Applied:
Verify the same URL manipulation no longer grants access without authentication📡 Detection & Monitoring
Log Indicators:
- HTTP requests containing '?images' in URL
- Unauthorized access to admin pages
- Configuration changes from unexpected IPs
Network Indicators:
- HTTP traffic to router management interface with ?images parameter
- Unusual outbound connections from router
SIEM Query:
http.url:*?images* AND (http.status:200 OR http.status:302) AND destination.ip:router_ip🔗 References
- http://www.securityfocus.com/bid/107053
- https://www.exploit-db.com/exploits/44576/
- https://www.vpnmentor.com/blog/critical-vulnerability-gpon-router/
- http://www.securityfocus.com/bid/107053
- https://www.exploit-db.com/exploits/44576/
- https://www.vpnmentor.com/blog/critical-vulnerability-gpon-router/
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-10561
