CVE-2025-3678
📋 TL;DR
A critical buffer overflow vulnerability in PCMan FTP Server 2.0.7 allows remote attackers to execute arbitrary code by sending specially crafted HELP commands. This affects all systems running the vulnerable FTP server version. Attackers can exploit this without authentication to potentially take full control of affected systems.
💻 Affected Systems
- PCMan FTP Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, ransomware deployment, or creation of persistent backdoors.
Likely Case
Remote code execution allowing attackers to install malware, exfiltrate data, or use the system as a foothold for lateral movement.
If Mitigated
Denial of service if exploit fails or crashes the service without code execution.
🎯 Exploit Status
Public exploit code is available, making exploitation straightforward for attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: No
Instructions:
No official patch available. Consider upgrading to a newer version if available or replacing with alternative FTP server software.
🔧 Temporary Workarounds
Disable FTP Service
windowsStop and disable the PCMan FTP Server service to prevent exploitation.
sc stop "PCMan FTP Server"
sc config "PCMan FTP Server" start= disabled
Network Segmentation
windowsRestrict network access to the FTP server using firewall rules.
netsh advfirewall firewall add rule name="Block PCMan FTP" dir=in action=block protocol=TCP localport=21
🧯 If You Can't Patch
- Replace PCMan FTP Server with a maintained alternative like FileZilla Server or vsftpd
- Implement strict network segmentation and firewall rules to limit access to the FTP server
🔍 How to Verify
Check if Vulnerable:
Check if PCMan FTP Server version 2.0.7 is installed and running on port 21.Check Version:
Check the application's About dialog or installation directory for version information.Verify Fix Applied:
Verify the service is stopped/disabled or that a different FTP server is running.📡 Detection & Monitoring
Log Indicators:
- Unusual HELP command patterns
- Service crashes or restarts
- Buffer overflow error messages
Network Indicators:
- Excessive or malformed HELP commands to FTP port 21
- Unusual traffic patterns to FTP server
SIEM Query:
source="ftp.log" AND (command="HELP" AND size>100) OR (message="buffer overflow" OR message="access violation")