CVE-2022-27947
📋 TL;DR
This vulnerability allows remote authenticated attackers to execute arbitrary commands on NETGEAR R8500 routers by injecting shell metacharacters into CGI parameters. Attackers can gain full system control, potentially enabling telnet access or other malicious activities. Only users with administrative access to the router's web interface are affected.
💻 Affected Systems
- NETGEAR R8500
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router leading to network interception, credential theft, malware deployment, and lateral movement into connected devices.
Likely Case
Unauthorized remote access to router configuration, network traffic monitoring, and potential credential harvesting from connected devices.
If Mitigated
Limited impact if strong authentication is enforced and network segmentation isolates the router management interface.
🎯 Exploit Status
Exploitation requires authenticated access but is straightforward once credentials are obtained. Public proof-of-concept demonstrates command injection via CGI parameters.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check NETGEAR for latest firmware (likely >1.0.2.158)
Vendor Advisory: https://kb.netgear.com/
Restart Required: Yes
Instructions:
1. Log into NETGEAR router admin interface. 2. Navigate to Advanced > Administration > Firmware Update. 3. Check for updates and apply latest firmware. 4. Reboot router after update completes.
🔧 Temporary Workarounds
Disable IPv6
allRemove attack vector by disabling IPv6 functionality
Log into router admin > Advanced > Advanced Setup > IPv6 > Disable IPv6
Restrict Management Access
allLimit router management interface to trusted IP addresses only
Log into router admin > Advanced > Security > Access Control > Enable Access Control
🧯 If You Can't Patch
- Change default admin credentials to strong, unique passwords
- Disable remote management and only allow local network access to admin interface
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin interface under Advanced > Administration > Router StatusCheck Version:
curl -k https://router-ip/currentsetting.htm | grep firmwareVerify Fix Applied:
Confirm firmware version is updated beyond 1.0.2.158 and test IPv6 configuration changes no longer execute commands📡 Detection & Monitoring
Log Indicators:
- Unusual CGI parameter values containing shell metacharacters
- Multiple failed login attempts followed by successful authentication
- Telnet service activation logs
Network Indicators:
- Unexpected telnet connections to router
- Unusual outbound connections from router
- Traffic to known malicious IPs from router
SIEM Query:
source="router.log" AND ("ipv6_fix.cgi" AND ("|" OR ";" OR "`" OR "$"))