CVE-2025-5220
📋 TL;DR
CVE-2025-5220 is a critical buffer overflow vulnerability in FreeFloat FTP Server 1.0.0's GET command handler that allows remote attackers to execute arbitrary code or crash the service. This affects all deployments of FreeFloat FTP Server 1.0.0 with the vulnerable component enabled. Attackers can exploit this without authentication over the network.
💻 Affected Systems
- FreeFloat FTP Server
📦 What is this software?
Ftp Server by Freefloat
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, and persistent backdoor installation
Likely Case
Service crash causing denial of service, with potential for remote code execution by skilled attackers
If Mitigated
Service disruption but limited lateral movement if properly segmented and monitored
🎯 Exploit Status
Public exploit code available, making exploitation trivial for attackers with basic skills
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: N/A
Restart Required: No
Instructions:
No official patch available. Consider migrating to alternative FTP server software with active maintenance.
🔧 Temporary Workarounds
Disable GET command
windowsRemove or restrict GET command functionality if not required
Configure server to disable GET command handler
Network segmentation
allRestrict access to FTP server to trusted networks only
Configure firewall rules to limit FTP port (default 21) access
🧯 If You Can't Patch
- Replace FreeFloat FTP Server with actively maintained alternative (FileZilla Server, vsftpd, etc.)
- Implement strict network segmentation and firewall rules to limit FTP access to essential hosts only
🔍 How to Verify
Check if Vulnerable:
Check if FreeFloat FTP Server version 1.0.0 is installed and runningCheck Version:
Check server interface or documentation for version informationVerify Fix Applied:
Verify FreeFloat FTP Server has been removed or replaced with alternative software📡 Detection & Monitoring
Log Indicators:
- Multiple failed GET commands with unusual parameters
- Server crash/restart events
- Unusual outbound connections from FTP server
Network Indicators:
- Excessive or malformed GET commands to FTP port
- Traffic patterns suggesting buffer overflow attempts
SIEM Query:
source="ftp_server.log" AND (GET AND (length>normal OR contains("\x90" OR "\x41")))