CVE-2023-37722
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on affected Tenda routers via a stack overflow in the fromSafeUrlFilter function. Attackers can exploit this by sending specially crafted requests to the vulnerable parameter. Users of Tenda F1202 and FH1202 routers with specific firmware versions are affected.
💻 Affected Systems
- Tenda F1202
- Tenda FH1202
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing persistent remote access, network traffic interception, and lateral movement to other devices on the network.
Likely Case
Remote code execution leading to router takeover, enabling attackers to modify DNS settings, intercept traffic, or use the device as a botnet node.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public proof-of-concept available in GitHub repository. Exploitation requires sending crafted HTTP request to vulnerable endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates. 2. Download latest firmware for your model. 3. Access router web interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Access router settings > Management > Disable Remote Management/Web Access from WAN
Network Segmentation
allIsolate router management interface from untrusted networks
Configure firewall rules to block inbound access to router management ports (typically 80, 443, 8080)
🧯 If You Can't Patch
- Replace affected routers with supported models from different vendors
- Place routers behind dedicated firewalls with strict inbound filtering rules
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface: System Status > Firmware VersionCheck Version:
curl -s http://router-ip/status.cgi | grep versionVerify Fix Applied:
Verify firmware version has been updated to a version later than the affected ones📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to router management endpoints
- Large payloads in URL parameters
- Multiple failed login attempts followed by exploitation attempts
Network Indicators:
- Unusual outbound connections from router
- DNS hijacking patterns
- Traffic redirection to suspicious IPs
SIEM Query:
source="router_logs" AND (url="*fromSafeUrlFilter*" OR parameter="*page*" AND size>1000)