CVE-2025-9581
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary commands on Comfast CF-N1 routers by injecting malicious input into the phy_interface parameter of the multi_pppoe function. It affects users of Comfast CF-N1 routers running firmware version 2.6.0, potentially enabling complete device compromise.
💻 Affected Systems
- Comfast CF-N1
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing attacker to install persistent backdoors, intercept network traffic, pivot to internal networks, or use device as botnet node.
Likely Case
Remote code execution leading to device takeover, credential theft, or network disruption.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Public exploit code available on GitHub. Attack requires sending crafted HTTP request to web interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check vendor website for firmware updates. 2. Download latest firmware. 3. Upload via web interface. 4. Reboot device.
🔧 Temporary Workarounds
Network Isolation
linuxRestrict access to web management interface using firewall rules.
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Disable PPPoE Interface
allRemove or disable vulnerable PPPoE functionality if not required.
🧯 If You Can't Patch
- Segment affected devices in isolated VLAN with strict firewall rules
- Implement network monitoring for suspicious web interface access patterns
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface or SSH: cat /etc/version | grep 2.6.0Check Version:
cat /etc/versionVerify Fix Applied:
Verify firmware version is updated beyond 2.6.0 and test with known exploit payloads.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to webmgnt with shell metacharacters in parameters
- Unexpected command execution in system logs
Network Indicators:
- HTTP requests containing command injection patterns (;, |, $, etc.) to router management interface
SIEM Query:
source="router_logs" AND (uri_path="/cgi-bin/webmgnt" AND request_body MATCHES "[;|$`]" )