CVE-2025-5667
📋 TL;DR
CVE-2025-5667 is a critical buffer overflow vulnerability in FreeFloat FTP Server 1.0's REIN command handler that allows remote attackers to execute arbitrary code or crash the service. This affects all deployments of FreeFloat FTP Server 1.0 with the vulnerable component enabled. Attackers can exploit this without authentication over the network.
💻 Affected Systems
- FreeFloat FTP Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, and persistent backdoor installation.
Likely Case
Service disruption through denial of service and potential remote code execution for initial foothold.
If Mitigated
Limited to service disruption if proper network segmentation and exploit prevention controls are in place.
🎯 Exploit Status
Public exploit code is available, making exploitation straightforward for attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: N/A
Restart Required: No
Instructions:
No official patch exists. Consider migrating to a maintained FTP server solution.
🔧 Temporary Workarounds
Disable FreeFloat FTP Server
windowsStop and disable the FreeFloat FTP Server service to prevent exploitation.
sc stop FreeFloatFTPServer
sc config FreeFloatFTPServer start= disabled
Block FTP Port at Firewall
windowsBlock external access to FTP port (default TCP/21) to prevent remote exploitation.
netsh advfirewall firewall add rule name="Block FTP" dir=in action=block protocol=TCP localport=21
🧯 If You Can't Patch
- Replace FreeFloat FTP Server with a maintained alternative like FileZilla Server or vsftpd.
- Implement strict network segmentation to isolate FTP server from critical systems.
🔍 How to Verify
Check if Vulnerable:
Check if FreeFloat FTP Server 1.0 is installed and running on the system.Check Version:
Check program files directory for FreeFloat FTP Server installation and version information.Verify Fix Applied:
Verify the service is stopped/disabled and port 21 is not listening.📡 Detection & Monitoring
Log Indicators:
- Multiple failed REIN command attempts
- Abnormal FTP service crashes
- Buffer overflow error messages in application logs
Network Indicators:
- Unusual traffic patterns to FTP port 21
- Exploit-specific payloads in network captures
SIEM Query:
source="ftp.log" AND (REIN OR "buffer overflow")