CVE-2023-37705
📋 TL;DR
This vulnerability in Tenda FH1203 routers allows remote attackers to execute arbitrary code via a stack overflow in the fromAddressNat function. Attackers can exploit this by sending specially crafted requests to the vulnerable device. All users running the affected firmware version are at risk.
💻 Affected Systems
- Tenda FH1203
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, and lateral movement to other devices on the network.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as part of a botnet.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Public proof-of-concept code exists in GitHub repositories, making exploitation straightforward for attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates
2. If update available, download and flash via web interface
3. Factory reset after update
4. Reconfigure with secure settings
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router administration interface
Network Segmentation
allIsolate router on separate VLAN to limit lateral movement
🧯 If You Can't Patch
- Replace vulnerable device with supported model
- Implement strict firewall rules blocking all inbound traffic to router management interface
🔍 How to Verify
Check if Vulnerable:
Check router web interface for firmware version. If version is V2.0.1.6, device is vulnerable.Check Version:
Check via router web interface at 192.168.0.1 or 192.168.1.1Verify Fix Applied:
Verify firmware version has been updated to a version later than V2.0.1.6📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to fromAddressNat endpoint
- Multiple failed login attempts followed by successful exploitation
Network Indicators:
- Unusual outbound connections from router
- Traffic patterns suggesting device compromise
SIEM Query:
source_ip=router_ip AND (uri_path="*fromAddressNat*" OR status_code=500)