CVE-2026-20704
📋 TL;DR
A cross-site request forgery (CSRF) vulnerability exists in ELECOM WRC-X1500GS-B and WRC-X1500GSA-B wireless routers. Attackers can trick authenticated users into performing unintended operations by visiting malicious web pages. This affects all users of these specific router models.
💻 Affected Systems
- ELECOM WRC-X1500GS-B
- ELECOM WRC-X1500GSA-B
⚠️ Risk & Real-World Impact
Worst Case
An attacker could change router settings, disable security features, redirect DNS, or potentially gain administrative access to the router configuration.
Likely Case
Attackers could modify network settings, change passwords, or disrupt network connectivity for users.
If Mitigated
With proper CSRF protections and user awareness, the risk is significantly reduced to minimal impact.
🎯 Exploit Status
Exploitation requires user interaction (visiting malicious page) while authenticated to router admin interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific firmware version
Vendor Advisory: https://www.elecom.co.jp/news/security/20260203-01/
Restart Required: Yes
Instructions:
1. Access router admin interface. 2. Navigate to firmware update section. 3. Download latest firmware from ELECOM website. 4. Upload and apply firmware update. 5. Reboot router after update completes.
🔧 Temporary Workarounds
Log out after router administration
allAlways log out of router admin interface immediately after making changes
Use separate browser for router admin
allUse a dedicated browser or private/incognito window only for router administration
🧯 If You Can't Patch
- Implement network segmentation to isolate router management interface
- Use browser extensions that block CSRF attempts
🔍 How to Verify
Check if Vulnerable:
Check router firmware version against vendor advisory. If using affected models with outdated firmware, assume vulnerable.Check Version:
Login to router admin interface and check firmware version in system statusVerify Fix Applied:
Verify firmware version matches or exceeds version specified in vendor advisory📡 Detection & Monitoring
Log Indicators:
- Unexpected configuration changes in router logs
- Multiple failed login attempts followed by successful changes
Network Indicators:
- Unusual DNS changes
- Unexpected port forwarding rules
- Changed admin credentials
SIEM Query:
Router logs showing configuration changes from unexpected IP addresses or without corresponding admin login events