CVE-2022-29391
📋 TL;DR
This vulnerability is a stack overflow in TOTOLINK N600R routers that allows remote code execution via the comment parameter in the setStaticDhcpConfig function. Attackers can exploit this to take full control of affected devices. Users of TOTOLINK N600R routers with vulnerable firmware are affected.
💻 Affected Systems
- TOTOLINK N600R
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to install persistent malware, pivot to internal networks, or join botnets.
Likely Case
Remote code execution leading to device takeover, credential theft, and network surveillance.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit code exists in GitHub repositories. The vulnerability is in a common administrative function.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
1. Check TOTOLINK website for firmware updates
2. If update available, download and flash via web interface
3. Verify firmware version after update
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router web interface
Access router admin panel > Advanced > Remote Management > Disable
Network segmentation
allIsolate router management interface from untrusted networks
Configure firewall rules to block WAN access to router management ports (typically 80, 443, 8080)
🧯 If You Can't Patch
- Replace affected devices with patched or different models
- Implement strict network access controls to limit exposure
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under System > Firmware UpgradeCheck Version:
curl -s http://router-ip/version or check web interfaceVerify Fix Applied:
Verify firmware version is newer than V4.3.0cu.7647_B20210106📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /cgi-bin/cstecgi.cgi with large comment parameters
- Multiple failed exploit attempts
Network Indicators:
- Unusual traffic to router management ports from external IPs
- Shellcode patterns in HTTP requests
SIEM Query:
source="router_logs" AND uri="/cgi-bin/cstecgi.cgi" AND (method="POST" OR params CONTAINS "comment")