CVE-2021-32424
📋 TL;DR
This CVE describes a Cross-Site Request Forgery (CSRF) vulnerability in TrendNet TW100-S4W1CA routers. An attacker can trick an authenticated user into visiting a malicious webpage that sends unauthorized commands to the router, potentially allowing complete takeover. This affects users of the vulnerable router firmware who have web-based administration enabled.
💻 Affected Systems
- TrendNet TW100-S4W1CA
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router takeover allowing attacker to change DNS settings, firewall rules, credentials, or install malicious firmware, leading to network compromise, data interception, or use as attack platform.
Likely Case
Router configuration changes leading to network disruption, credential theft, or redirection to malicious sites for users on the network.
If Mitigated
No impact if proper CSRF protections are implemented or if users don't visit malicious sites while authenticated to router admin.
🎯 Exploit Status
Exploit requires user interaction (visiting malicious page) while authenticated to router admin. Proof-of-concept available in GitHub repository.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not found
Restart Required: No
Instructions:
Check TrendNet website for firmware updates. If available, download latest firmware and upload via router admin interface under System Tools > Firmware Upgrade.
🔧 Temporary Workarounds
Enable CSRF Protection
allImplement anti-CSRF tokens in web interface if router supports custom configuration
Restrict Admin Access
allLimit router admin interface access to specific IP addresses or disable remote admin
🧯 If You Can't Patch
- Log out of router admin interface immediately after use
- Use separate browser or incognito mode for router administration only
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under Status > Device Info. If version is 2.3.32, device is vulnerable.Check Version:
Check via web interface or use curl: curl -s http://router-ip/status_deviceinfo.htm | grep FirmwareVerify Fix Applied:
Verify firmware version has been updated to a version higher than 2.3.32📡 Detection & Monitoring
Log Indicators:
- Multiple configuration changes from same IP in short time
- Unauthorized admin login attempts followed by config changes
Network Indicators:
- Unusual outbound connections from router
- DNS changes to suspicious domains
SIEM Query:
source="router.log" AND (event="configuration_change" OR event="admin_login") | stats count by src_ip, user