CVE-2025-5593
📋 TL;DR
A critical buffer overflow vulnerability in FreeFloat FTP Server 1.0's HOST command handler allows remote attackers to execute arbitrary code or crash the service. This affects all deployments of FreeFloat FTP Server 1.0. 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, or ransomware deployment.
Likely Case
Service crash causing denial of service, potentially followed by remote code execution.
If Mitigated
Service crash only if exploit fails, but still causes availability impact.
🎯 Exploit Status
Public exploit code is 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 exists. Replace FreeFloat FTP Server with a maintained alternative like FileZilla Server, vsftpd, or ProFTPD.
🔧 Temporary Workarounds
Disable FreeFloat FTP Server
windowsStop and disable the FreeFloat FTP Server service immediately.
sc stop FreeFloatFTPServer
sc config FreeFloatFTPServer start= disabled
Block FTP port at firewall
windowsBlock external access to FTP port (typically TCP 21) at network perimeter.
netsh advfirewall firewall add rule name="Block FTP" dir=in action=block protocol=TCP localport=21
🧯 If You Can't Patch
- Isolate affected systems in separate network segment with strict firewall rules
- Implement network-based intrusion prevention to detect and block exploit attempts
🔍 How to Verify
Check if Vulnerable:
Check if FreeFloat FTP Server 1.0 is installed and running on port 21/TCP.Check Version:
Check installed programs in Control Panel or run: wmic product get name,version | findstr FreeFloatVerify Fix Applied:
Verify FreeFloat FTP Server is no longer running and port 21 is closed or blocked.📡 Detection & Monitoring
Log Indicators:
- Multiple failed HOST command attempts
- Unusually long HOST command parameters
- Service crash logs
Network Indicators:
- Excessive traffic to FTP port 21 with malformed HOST commands
- Buffer overflow patterns in FTP traffic
SIEM Query:
source="*ftp*" AND ("HOST" AND length>100) OR "buffer overflow" OR "access violation"