CVE-2018-14714
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary system commands on ASUS RT-AC3200 routers via command injection in the appGet.cgi script. Attackers can exploit this by sending specially crafted requests with malicious commands in the 'load_script' URL parameter. Only users running the specific vulnerable firmware version on ASUS RT-AC3200 routers are affected.
💻 Affected Systems
- ASUS RT-AC3200
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router allowing attackers to install persistent malware, intercept all network traffic, pivot to internal network devices, and use the router as part of a botnet.
Likely Case
Attackers gain remote code execution on the router, potentially changing DNS settings to redirect traffic, stealing credentials, or disabling security features.
If Mitigated
If the router is behind a firewall with strict inbound rules and not exposed to the internet, the attack surface is significantly reduced to only internal threats.
🎯 Exploit Status
The exploit requires no authentication and can be triggered via a simple HTTP request. Public technical details are available in security blogs.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Later versions than 3.0.0.4.382.50010
Vendor Advisory: https://www.asus.com/support/FAQ/1044144/
Restart Required: Yes
Instructions:
1. Log into ASUS router admin interface. 2. Navigate to Administration > Firmware Upgrade. 3. Check for updates and install the latest firmware. 4. Reboot the router after installation completes.
🔧 Temporary Workarounds
Disable Remote Management
allPrevents external attackers from accessing the vulnerable web interface by disabling WAN-side administration.
Navigate to Administration > System > Enable Web Access from WAN: Set to No
Restrict Web Interface Access
allLimit access to the router's web interface to trusted IP addresses only using firewall rules.
Navigate to Firewall > General > Enable Firewall: Yes
Add rules to restrict port 80/443 access to specific IPs
🧯 If You Can't Patch
- Isolate the router on a dedicated network segment with strict firewall rules preventing inbound internet access to the web interface.
- Implement network monitoring to detect suspicious HTTP requests to appGet.cgi with command injection patterns.
🔍 How to Verify
Check if Vulnerable:
Check current firmware version in router admin interface under Administration > Firmware Upgrade. If version is exactly 3.0.0.4.382.50010, the device is vulnerable.Check Version:
curl -s http://router-ip/Main_Login.asp | grep -i firmwareVerify Fix Applied:
After updating, verify the firmware version is higher than 3.0.0.4.382.50010. Test by attempting to access appGet.cgi with test parameters to confirm proper input validation.📡 Detection & Monitoring
Log Indicators:
- HTTP requests to /appGet.cgi with suspicious parameters containing shell metacharacters like ;, |, &, $, (, )
- Unusual process execution from web server context
Network Indicators:
- HTTP POST/GET requests to router IP on port 80/443 containing 'load_script' parameter with command injection patterns
SIEM Query:
source="router_logs" AND (url="*appGet.cgi*" AND (param="*load_script=*;*" OR param="*load_script=*|*" OR param="*load_script=*&*" OR param="*load_script=*$(*"))