CVE-2023-38928
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary commands on Netgear R7100LG routers by injecting malicious code into the password parameter of the usb_remote_invite.cgi script. Attackers can gain full control of affected devices, potentially compromising network security. Only Netgear R7100LG routers running vulnerable firmware versions are affected.
💻 Affected Systems
- Netgear R7100LG
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover leading to persistent backdoor installation, network traffic interception, lateral movement to other devices, and potential data exfiltration.
Likely Case
Remote code execution allowing attackers to modify device settings, install malware, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation is implemented.
🎯 Exploit Status
Exploit requires network access to the device's web interface; command injection is straightforward once the vulnerable endpoint is identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.netgear.com/about/security/
Restart Required: Yes
Instructions:
1. Check Netgear security advisory for firmware updates. 2. Download latest firmware from Netgear support site. 3. Log into router admin interface. 4. Navigate to Advanced > Administration > Firmware Update. 5. Upload and install new firmware. 6. Reboot router after installation.
🔧 Temporary Workarounds
Disable USB Remote Invite
allTurn off the vulnerable USB remote invite feature to prevent exploitation
Restrict Network Access
linuxBlock external access to router admin interface using firewall rules
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict access controls
- Implement network monitoring for suspicious traffic to/from router management interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface at Advanced > Administration > Router StatusCheck Version:
curl -s http://router-ip/currentsetting.htm | grep FirmwareVerify Fix Applied:
Verify firmware version is updated beyond 1.0.0.78 and test usb_remote_invite.cgi endpoint with safe payloads📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to usb_remote_invite.cgi
- Suspicious command execution in system logs
- Multiple failed login attempts
Network Indicators:
- Unexpected outbound connections from router
- Traffic to known malicious IPs
- Unusual port scanning from router
SIEM Query:
source="router.log" AND (uri="/usb_remote_invite.cgi" OR cmd="*;*" OR cmd="*|*")