CVE-2023-24479
📋 TL;DR
An authentication bypass vulnerability in the httpd nvram.cgi functionality of Yifan YF325 routers allows unauthenticated attackers to execute arbitrary commands. This affects Yifan YF325 routers running firmware version v1.0_20221108. Attackers can gain complete control of affected devices.
💻 Affected Systems
- Yifan YF325
📦 What is this software?
Yf325 Firmware by Yifanwireless
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to network infiltration, data exfiltration, ransomware deployment, or use as botnet node.
Likely Case
Router takeover for credential theft, network surveillance, or lateral movement into connected networks.
If Mitigated
Limited impact if device is isolated behind firewalls with strict network segmentation.
🎯 Exploit Status
Exploitation requires sending a specially crafted HTTP request to the nvram.cgi endpoint. No authentication needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No vendor advisory found
Restart Required: No
Instructions:
No official patch available. Consider replacing affected devices or implementing strict network controls.
🔧 Temporary Workarounds
Network Isolation
linuxPlace YF325 routers behind firewalls and restrict access to management interfaces.
iptables -A INPUT -p tcp --dport 80 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
Disable HTTP Management
linuxDisable HTTP management interface if alternative management methods exist.
killall httpd
rm /etc/init.d/S80httpd
🧯 If You Can't Patch
- Segment network to isolate YF325 routers from critical systems
- Implement strict firewall rules blocking all external access to router management interfaces
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface or SSH: cat /etc/versionCheck Version:
cat /etc/versionVerify Fix Applied:
No official fix available. Verify workarounds by testing HTTP access to nvram.cgi endpoint.📡 Detection & Monitoring
Log Indicators:
- HTTP requests to /nvram.cgi with unusual parameters
- Multiple failed authentication attempts followed by successful nvram.cgi access
Network Indicators:
- HTTP POST requests to nvram.cgi from untrusted sources
- Unusual outbound connections from router
SIEM Query:
source="router_logs" AND uri="/nvram.cgi" AND (method="POST" OR params CONTAINS "exec" OR params CONTAINS "cmd")