CVE-2025-3679
📋 TL;DR
A critical buffer overflow vulnerability in PCMan FTP Server 2.0.7 allows remote attackers to execute arbitrary code or crash the service by sending specially crafted HOST commands. This affects anyone running the vulnerable FTP server version. The exploit is publicly available, increasing the risk of attacks.
💻 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, or ransomware deployment.
Likely Case
Service crash causing denial of service, potentially followed by remote code execution attempts.
If Mitigated
Limited to denial of service if exploit fails or controls block execution.
🎯 Exploit Status
Exploit code is publicly available at the provided references, making attacks easy to launch.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None known
Restart Required: No
Instructions:
No official patch is available. Consider upgrading to a newer version if released, or apply workarounds.
🔧 Temporary Workarounds
Disable FTP Server
windowsStop and disable the PCMan FTP Server service to prevent exploitation.
sc stop "PCMan FTP Server"
sc config "PCMan FTP Server" start= disabled
Block HOST Command via Firewall
windowsConfigure firewall rules to block FTP traffic or specifically filter HOST commands.
netsh advfirewall firewall add rule name="Block FTP" dir=in action=block protocol=TCP localport=21
🧯 If You Can't Patch
- Replace PCMan FTP Server with a secure alternative like FileZilla Server or vsftpd.
- Isolate the FTP server in a segmented network with strict access controls.
🔍 How to Verify
Check if Vulnerable:
Check if PCMan FTP Server version 2.0.7 is installed via Programs and Features or by examining the executable properties.Check Version:
wmic product where name="PCMan FTP Server" get versionVerify Fix Applied:
Verify the server is no longer running or has been upgraded to a non-vulnerable version.📡 Detection & Monitoring
Log Indicators:
- FTP server crash logs
- Unusual HOST command usage in FTP logs
- Error messages related to buffer overflow
Network Indicators:
- Excessive or malformed HOST commands sent to FTP port 21
- Traffic patterns matching known exploit signatures
SIEM Query:
source="ftp.log" AND (command="HOST" AND length>threshold) OR event="crash"