CVE-2023-50987
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on Tenda i29 routers by sending specially crafted requests to the sysTimeInfoSet function. Attackers can exploit this buffer overflow to gain full control of affected devices. All users running vulnerable firmware versions are affected.
💻 Affected Systems
- Tenda i29
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, lateral movement to other devices, and botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public proof-of-concept available on GitHub demonstrates exploitation. Buffer overflow in time parameter allows straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: http://tenda.com
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates
2. Download latest firmware for i29 model
3. Access router web interface
4. Navigate to System Tools > Firmware Upgrade
5. Upload and apply new firmware
6. Reboot router
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Access router web interface > System Tools > Remote Management > Disable
Network Segmentation
linuxIsolate router management interface to trusted network
iptables -A INPUT -p tcp --dport 80 -s TRUSTED_NETWORK -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Place router behind firewall with strict inbound filtering
- Implement network monitoring for exploit attempts
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface: System Status > Firmware VersionCheck Version:
curl -s http://router-ip/status.cgi | grep firmwareVerify Fix Applied:
Verify firmware version is newer than V1.0.0.5📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/sysTimeInfoSet
- Large time parameter values in HTTP requests
- Router reboot or configuration changes
Network Indicators:
- HTTP POST requests with oversized time parameters
- Traffic to router management port from unusual sources
SIEM Query:
source="router_logs" AND (uri_path="/goform/sysTimeInfoSet" OR time_parameter_length>100)