CVE-2025-5219
📋 TL;DR
A critical buffer overflow vulnerability exists in FreeFloat FTP Server 1.0.0's ASCII Command Handler component. This allows remote attackers to execute arbitrary code or crash the service by sending specially crafted commands. Anyone running FreeFloat FTP Server 1.0.0 is affected.
💻 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, or ransomware deployment.
Likely Case
Service crash causing denial of service, potentially followed by remote code execution.
If Mitigated
Service crash only, with no further system impact if proper isolation exists.
🎯 Exploit Status
Public exploit code is available, making exploitation straightforward for attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: None
Vendor Advisory: None
Restart Required: No
Instructions:
No official patch exists. Consider migrating to a supported FTP server solution.
🔧 Temporary Workarounds
Disable ASCII mode
windowsConfigure FTP server to only allow binary transfers, bypassing the vulnerable ASCII handler.
Network segmentation
windowsRestrict FTP server access to trusted networks only using firewall rules.
netsh advfirewall firewall add rule name="Block FTP External" dir=in action=block protocol=TCP localport=21 remoteip=any
🧯 If You Can't Patch
- Replace FreeFloat FTP Server with a maintained alternative like FileZilla Server or vsftpd.
- Implement strict network access controls and monitor for exploitation attempts.
🔍 How to Verify
Check if Vulnerable:
Check if FreeFloat FTP Server version 1.0.0 is installed and running.Check Version:
Check program files directory for FreeFloat FTP Server installation and version information.Verify Fix Applied:
Verify the service has been removed or replaced with a secure alternative.📡 Detection & Monitoring
Log Indicators:
- Multiple failed ASCII mode connection attempts
- Unusual ASCII command patterns
- Service crash logs
Network Indicators:
- Excessive traffic to FTP port 21 with ASCII mode commands
- Buffer overflow patterns in packet captures
SIEM Query:
source="ftp.log" AND (event="ASCII" OR event="buffer overflow")