CVE-2023-41552
📋 TL;DR
This CVE describes a critical stack overflow vulnerability in Tenda AC7 and AC9 routers that allows remote code execution. Attackers can exploit this by sending specially crafted requests to the vulnerable endpoint, potentially taking full control of affected devices. All users of the specified router models with vulnerable firmware versions are affected.
💻 Affected Systems
- Tenda AC7
- Tenda AC9
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, credential theft, network traffic interception, and use as pivot point for attacking other internal systems.
Likely Case
Remote code execution allowing attacker to modify router settings, intercept traffic, or use device as part of botnet.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Public proof-of-concept available in GitHub repository. Exploitation requires sending HTTP POST request to vulnerable endpoint with crafted ssid parameter.
🛠️ 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 firmware
3. Factory reset router after update
4. Reconfigure with secure settings
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router management interface
Network Segmentation
allPlace router in isolated network segment with restricted access
🧯 If You Can't Patch
- Replace vulnerable routers with patched or different models
- Implement strict firewall rules blocking all WAN access to router management interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at 192.168.0.1 or 192.168.1.1Check Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
Verify firmware version is newer than affected versions and test if /goform/fast_setting_wifi_set endpoint still exists📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /goform/fast_setting_wifi_set with unusually long ssid parameter
- Router crash/reboot logs
Network Indicators:
- Unusual outbound connections from router
- HTTP requests with buffer overflow patterns
SIEM Query:
source="router_logs" AND uri="/goform/fast_setting_wifi_set" AND content_length>1000