CVE-2021-44247
📋 TL;DR
This CVE describes a command injection vulnerability in Totolink router firmware that allows attackers to execute arbitrary commands via the IpFrom parameter in the setNoticeCfg function. Attackers can gain full control of affected devices, potentially compromising network security. Users of Totolink A3100R, A830R, and A720R routers with specific vulnerable firmware versions are affected.
💻 Affected Systems
- Totolink A3100R
- Totolink A830R
- Totolink A720R
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover leading to network compromise, data exfiltration, lateral movement to other devices, and persistent backdoor installation.
Likely Case
Router compromise allowing traffic interception, DNS manipulation, credential theft, and use as attack platform.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit details available in GitHub repository; command injection via IpFrom parameter is straightforward to exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Totolink website for firmware updates
2. Download latest firmware for your model
3. Access router admin interface
4. Navigate to firmware upgrade section
5. Upload and apply new firmware
6. Reboot router after update
🔧 Temporary Workarounds
Disable remote administration
allPrevent external access to router administration interface
Network segmentation
allIsolate routers in separate VLAN with strict firewall rules
🧯 If You Can't Patch
- Replace affected devices with patched or different vendor equipment
- Implement strict network access controls and monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Status or Firmware Upgrade sectionCheck Version:
Login to router web interface and check firmware version in system informationVerify Fix Applied:
Verify firmware version has changed from vulnerable versions listed in affected systems📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Multiple failed login attempts to admin interface
- Unexpected configuration changes
Network Indicators:
- Unusual outbound connections from router
- DNS queries to suspicious domains
- Port scanning originating from router
SIEM Query:
source="router_logs" AND ("command injection" OR "IpFrom" OR "setNoticeCfg")