CVE-2022-27016
📋 TL;DR
A stack overflow vulnerability in the SetStaticRouteCfg() function of Tenda AC9 router's httpd service allows remote code execution. This affects Tenda AC9 router users running vulnerable firmware versions. Attackers can exploit this to take complete control of affected devices.
💻 Affected Systems
- Tenda AC9
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote attacker gains full root access to the router, enabling traffic interception, credential theft, network pivoting, and persistent backdoor installation.
Likely Case
Router compromise leading to DNS hijacking, credential harvesting, and botnet recruitment for DDoS attacks.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Public exploit code available in GitHub repositories. Stack overflow allows RCE with minimal prerequisites.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not found
Restart Required: Yes
Instructions:
1. Check Tenda support for firmware updates. 2. If update available, download from official site. 3. Upload via web interface. 4. Factory reset after update. 5. Reconfigure securely.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to web management interface
Network Segmentation
allIsolate router management interface to trusted network
🧯 If You Can't Patch
- Replace vulnerable device with supported model
- Implement strict firewall rules blocking all WAN access to router management interface
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface. If version is 15.03.2.21_cn or earlier, assume vulnerable.Check Version:
Not applicable - check via web interface at 192.168.0.1 or device IPVerify Fix Applied:
Verify firmware version is updated beyond 15.03.2.21_cn. Test web interface functionality remains intact.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/SetStaticRouteCfg
- Multiple failed login attempts followed by successful exploit
Network Indicators:
- Unusual outbound connections from router
- DNS queries to malicious domains
- Unexpected port scans originating from router
SIEM Query:
source_ip=router_ip AND (uri_path="/goform/SetStaticRouteCfg" OR http_method=POST AND user_agent_contains="exploit")