CVE-2022-21809
📋 TL;DR
This vulnerability allows attackers to upload arbitrary malicious files to InHand Networks InRouter302 devices via the upload.cgi functionality. Exploitation can lead to remote code execution, device compromise, or network infiltration. Organizations using affected InRouter302 devices are at risk.
💻 Affected Systems
- InHand Networks InRouter302
📦 What is this software?
Inrouter302 Firmware by Inhandnetworks
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover leading to network pivot, data exfiltration, or deployment of persistent malware across connected systems.
Likely Case
Unauthorized file upload enabling web shell installation for remote command execution and device control.
If Mitigated
Limited impact with proper network segmentation and access controls preventing external exploitation.
🎯 Exploit Status
Exploitation requires crafting a malicious HTTP request to the upload.cgi endpoint. No authentication is needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V3.5.5 or later
Vendor Advisory: https://www.inhandnetworks.com/upload/attachment/202205/10/InHand-PSA-2022-01.pdf
Restart Required: Yes
Instructions:
1. Download firmware update from InHand Networks support portal. 2. Access device web interface. 3. Navigate to System > Upgrade. 4. Upload firmware file. 5. Apply update and reboot device.
🔧 Temporary Workarounds
Disable HTTP upload functionality
linuxTemporarily disable or restrict access to upload.cgi endpoint
# Modify web server configuration to block upload.cgi
# Use iptables: iptables -A INPUT -p tcp --dport 80 -m string --string "upload.cgi" --algo bm -j DROP
Network access control
linuxRestrict access to device management interface
# Firewall rule to limit access: iptables -A INPUT -p tcp --dport 80 -s trusted_ip -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Isolate affected devices in separate VLAN with strict firewall rules
- Implement web application firewall (WAF) to block malicious upload requests
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or SSH: cat /etc/versionCheck Version:
cat /etc/version || grep -i version /proc/cpuinfoVerify Fix Applied:
Verify firmware version is V3.5.5 or later and test upload functionality with safe test files📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /cgi-bin/upload.cgi
- Unusual file uploads in web server logs
- Large or suspicious file upload attempts
Network Indicators:
- HTTP traffic to upload.cgi endpoint from untrusted sources
- Unusual outbound connections from device after upload
SIEM Query:
source="web_logs" AND uri="/cgi-bin/upload.cgi" AND method="POST" AND size>1000000