CVE-2025-5665
📋 TL;DR
CVE-2025-5665 is a critical buffer overflow vulnerability in FreeFloat FTP Server 1.0's XCWD command handler that allows remote attackers to execute arbitrary code or crash the service. This affects all deployments of FreeFloat FTP Server 1.0. The vulnerability is remotely exploitable without authentication.
💻 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 disruption through denial of service or limited code execution in constrained environments.
If Mitigated
Service crash with no further impact if proper network segmentation and least privilege are implemented.
🎯 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
Network Access Control
windowsRestrict access to FreeFloat FTP Server using firewall rules to only trusted IP addresses.
# Windows Firewall: New-NetFirewallRule -DisplayName "Block FreeFloat FTP" -Direction Inbound -Protocol TCP -LocalPort 21 -Action Block
Service Disablement
windowsDisable or uninstall FreeFloat FTP Server if not required.
sc stop FreeFloatFTP
sc config FreeFloatFTP start= disabled
🧯 If You Can't Patch
- Isolate the vulnerable server in a dedicated network segment with strict firewall rules.
- Implement application allowlisting to prevent execution of unauthorized code.
🔍 How to Verify
Check if Vulnerable:
Check if FreeFloat FTP Server 1.0 is installed and running on port 21/TCP.Check Version:
Check program files directory for FreeFloat FTP Server files and version information.Verify Fix Applied:
Verify the service is stopped/removed or network access is properly restricted.📡 Detection & Monitoring
Log Indicators:
- Unusual XCWD command patterns
- Service crash logs
- Buffer overflow error messages
Network Indicators:
- Excessive or malformed XCWD commands to port 21
- Traffic patterns matching known exploit
SIEM Query:
source="FreeFloat FTP Server" AND (event="XCWD" OR event="buffer overflow" OR event="crash")