CVE-2017-15222
📋 TL;DR
A buffer overflow vulnerability in Ayukov NFTPD 2.0 and earlier allows remote attackers to execute arbitrary code on affected FTP servers. This affects systems running vulnerable versions of Ayukov NFTPD, potentially giving attackers full control over the server.
💻 Affected Systems
- Ayukov NFTPD
📦 What is this software?
Nftp by Nftp Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, and persistent backdoor installation.
Likely Case
Remote code execution allowing attackers to run arbitrary commands, steal data, or use the server as a pivot point.
If Mitigated
Limited impact if proper network segmentation and least privilege controls prevent lateral movement.
🎯 Exploit Status
Multiple public exploits exist, making this easily exploitable by attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch exists. Upgrade to a different FTP server software or implement workarounds.
🔧 Temporary Workarounds
Network Segmentation
allRestrict FTP server access to trusted networks only using firewall rules.
# Example iptables rule: iptables -A INPUT -p tcp --dport 21 -s TRUSTED_NETWORK -j ACCEPT
# Example Windows Firewall: New-NetFirewallRule -DisplayName 'Restrict FTP' -Direction Inbound -Protocol TCP -LocalPort 21 -RemoteAddress TRUSTED_NETWORK -Action Allow
Replace with Secure FTP Server
allMigrate to a maintained, secure FTP server alternative.
# For Linux: apt-get install vsftpd
# For Windows: Consider FileZilla Server or other maintained alternatives
🧯 If You Can't Patch
- Implement strict network access controls to limit FTP server exposure
- Monitor FTP server logs for unusual activity and implement intrusion detection
🔍 How to Verify
Check if Vulnerable:
Check NFTPD version: On Windows check program version in About dialog or installation directory. On Linux check version via command line if available.Check Version:
Windows: Check program properties. Linux: Check if nftpd binary exists and version info.Verify Fix Applied:
Verify NFTPD is no longer running or has been replaced with alternative software.📡 Detection & Monitoring
Log Indicators:
- Unusual FTP connection patterns
- Failed authentication attempts followed by buffer overflow patterns
- Unexpected process execution from FTP service
Network Indicators:
- Unusual FTP traffic patterns
- Exploit payloads in FTP protocol traffic
- Outbound connections from FTP server to suspicious IPs
SIEM Query:
source="ftp.log" AND ("buffer overflow" OR "exploit" OR unusual_command_length>1000)🔗 References
- http://www.securityfocus.com/bid/101602
- https://www.exploit-db.com/exploits/43025/
- https://www.exploit-db.com/exploits/43448/
- https://www.exploit-db.com/exploits/46070/
- http://www.securityfocus.com/bid/101602
- https://www.exploit-db.com/exploits/43025/
- https://www.exploit-db.com/exploits/43448/
- https://www.exploit-db.com/exploits/46070/
