Module: Msf::Exploit::Remote::SMB::Server::Share::Command::Negotiate

Included in:
Msf::Exploit::Remote::SMB::Server::Share
Defined in:
lib/msf/core/exploit/smb/server/share/command/negotiate.rb

Instance Method Summary collapse

Instance Method Details

#send_negotitate_res(c, opts = {}) ⇒ Integer

Builds and sends an SMB_COM_CLOSE response.

Parameters:

  • c (Socket) —

    The client to answer.

  • opts (Hash{Symbol => <String, Integer>}) (defaults to: {}) —

    Response custom values.

Options Hash (opts):

  • :dialect (Integer) —

    The index of the dialect selected by the server from the request.

  • :security_mode (Integer) —

    Security modes supported or required by the server.

  • :max_mpx (Integer) —

    The maximum number of outstanding SMB operations that the server supports.

  • :max_vcs (Integer) —

    The maximum number of virtual circuits between the client and the server.

  • :max_buff (Integer) —

    Largest SMB message that the server can handle.

  • :max_raw (Integer) —

    Max size for SMB_COM_WRITE_RAW requests and SMB_COM_READ_RAW responses.

  • :server_time_zone (Integer) —

    The server's time zone.

  • :capabilities (Integer) —

    The server capability indicators.

  • :key_length (Integer) —

    The challenge length.

  • :key (String) —

    The challenge.

Returns:

  • (Integer) —

    The number of bytes returned to the client as response.


51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
 
# File 'lib/msf/core/exploit/smb/server/share/command/negotiate.rb', line 51

def send_negotitate_res(c, opts = {})
  dialect = opts[:dialect] || 0
  security_mode = opts[:security_mode] || 0
  max_mpx = opts[:max_mpx] || 0
  max_vcs = opts[:max_vcs] || 0
  max_buff = opts[:max_buff] || 0
  max_raw = opts[:max_raw] || 0
  server_time_zone = opts[:server_time_zone] || 0
  capabilities = opts[:capabilities] || 0
  key_length = opts[:key_length] || 0
  key = opts[:key] || ''

  pkt = CONST::SMB_NEG_RES_NT_PKT.make_struct
  smb_set_defaults(c, pkt)

  pkt['Payload']['SMB'].v['Command'] = CONST::SMB_COM_NEGOTIATE
  pkt['Payload']['SMB'].v['Flags1'] = FLAGS
  pkt['Payload']['SMB'].v['Flags2'] = FLAGS2
  pkt['Payload']['SMB'].v['WordCount'] = CONST::SMB_NEGOTIATE_RES_WORD_COUNT
  pkt['Payload'].v['Dialect'] = dialect
  pkt['Payload'].v['SecurityMode'] = security_mode
  pkt['Payload'].v['MaxMPX'] = max_mpx
  pkt['Payload'].v['MaxVCS'] = max_vcs
  pkt['Payload'].v['MaxBuff'] = max_buff
  pkt['Payload'].v['MaxRaw'] = max_raw
  pkt['Payload'].v['SystemTimeLow'] = lo
  pkt['Payload'].v['SystemTimeHigh'] = hi
  pkt['Payload'].v['ServerTimeZone'] = server_time_zone
  pkt['Payload'].v['SessionKey'] = 0
  pkt['Payload'].v['Capabilities'] = capabilities
  pkt['Payload'].v['KeyLength'] = key_length
  pkt['Payload'].v['Payload'] = key

  c.put(pkt.to_s)
end

#smb_cmd_negotiate(c, buff) ⇒ Integer

Handles an SMB_COM_NEGOTIATE command, used by the client to initiate an SMB connection between the client and the server.

Parameters:

  • c (Socket) —

    The client sending the request.

  • buff (String) —

    The data including the client request.

Returns:

  • (Integer) —

    The number of bytes returned to the client as response.


15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
 
# File 'lib/msf/core/exploit/smb/server/share/command/negotiate.rb', line 15

def smb_cmd_negotiate(c, buff)
  pkt = CONST::SMB_NEG_PKT.make_struct
  pkt.from_s(buff)

  dialects = pkt['Payload'].v['Payload'].gsub(/\x00/, '').split(/\x02/).grep(/^\w+/)
  dialect = dialects.index("NT LM 0.12") || dialects.length-1

  send_negotitate_res(c, {
    dialect: dialect,
    security_mode: CONST::NEG_SECURITY_PASSWORD,
    max_mpx: 50,
    max_vcs: 1,
    max_buff: 4356,
    max_raw: 65536,
    server_time_zone: 0,
    capabilities: CAPABILITIES,
    key_length: 8,
    key: Rex::Text.rand_text_hex(8)
  })
end