CVE-2022-27003
📋 TL;DR
This CVE describes a critical command injection vulnerability in Totolink routers that allows attackers to execute arbitrary system commands via the Tunnel 6rd function. Attackers can exploit this by sending specially crafted requests containing malicious commands in the relay6rd parameter. Users of affected Totolink router models with vulnerable firmware versions are at risk.
💻 Affected Systems
- Totolink X5000R
- Totolink A7000R
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router allowing attackers to install persistent backdoors, intercept all network traffic, pivot to internal networks, and use the router for botnet activities.
Likely Case
Remote code execution leading to router configuration changes, credential theft, DNS hijacking, and network disruption.
If Mitigated
Limited impact if routers are behind firewalls with strict inbound filtering and command injection protections are implemented.
🎯 Exploit Status
Public proof-of-concept code exists in GitHub repositories showing exploitation via crafted HTTP requests to the vulnerable endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not publicly available
Restart Required: Yes
Instructions:
1. Check Totolink website for firmware updates
2. If update available, download and verify checksum
3. Access router admin interface
4. Navigate to firmware update section
5. Upload new firmware file
6. Wait for installation and router reboot
7. Verify new firmware version
🔧 Temporary Workarounds
Disable Tunnel 6rd Function
allDisable the vulnerable Tunnel 6rd feature if not required for network operations
Network Segmentation
allPlace routers in isolated network segments with strict firewall rules
🧯 If You Can't Patch
- Implement strict network access controls to limit exposure to router management interfaces
- Deploy web application firewall (WAF) with command injection protection rules
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface and compare with affected versions. Test with controlled exploit attempt in isolated environment.Check Version:
Login to router admin interface and check System Status or Firmware Information pageVerify Fix Applied:
Verify firmware version has been updated beyond vulnerable versions. Test that command injection attempts no longer succeed.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to router management interface
- Commands containing shell metacharacters in relay6rd parameter
- Unexpected system processes or configuration changes
Network Indicators:
- Unusual outbound connections from router
- Traffic patterns suggesting command and control communication
- DNS queries to suspicious domains
SIEM Query:
source="router_logs" AND ("relay6rd" OR "6rd") AND ("|" OR ";" OR "$" OR "`" OR "&&")