CVE-2023-38866
📋 TL;DR
COMFAST CF-XR11 V2.7.2 contains a command injection vulnerability in the web management interface. Attackers can send specially crafted POST requests to execute arbitrary commands on the device with root privileges. This affects all users of the vulnerable firmware version.
💻 Affected Systems
- COMFAST CF-XR11
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full device compromise allowing attackers to install persistent backdoors, pivot to internal networks, or use the device for botnet participation.
Likely Case
Remote code execution leading to device takeover, credential theft, and network reconnaissance.
If Mitigated
Limited impact if device is behind strict firewall rules and not internet-facing.
🎯 Exploit Status
Public proof-of-concept available on GitHub. Exploitation requires only HTTP POST requests with command injection payloads.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch available. Check vendor website for firmware updates. If unavailable, implement workarounds.
🔧 Temporary Workarounds
Network Segmentation
allIsolate vulnerable device from internet and restrict internal network access.
Firewall Rules
linuxBlock access to web management interface (port 80/443) from untrusted networks.
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Replace device with non-vulnerable model
- Implement strict network access controls and monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface or SSH. Version V2.7.2 is vulnerable.Check Version:
cat /etc/version or check web interface system infoVerify Fix Applied:
Verify firmware version is updated beyond V2.7.2. Test with non-destructive payload like 'id' command.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /usr/bin/webmgnt
- Commands with shell metacharacters in interface or display_name parameters
Network Indicators:
- HTTP POST requests containing shell commands (;, |, &, $()) in parameters
SIEM Query:
http.method:POST AND http.uri:"/usr/bin/webmgnt" AND (http.param:*;* OR http.param:*|* OR http.param:*&* OR http.param:*$(*))