Class: Rex::Post::Meterpreter::Extensions::Stdapi::Sys::ProcessSubsystem::Memory

Inherits:
Object
  • Object
show all
Defined in:
lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb

Overview

Provides an interface to allocate, free, read, write, query, protect, lock, and unlock memory in the context of a given process.

Constant Summary collapse

@@page_protection_map =

Page protection translation hash

{
  PROT_NONE                => PAGE_NOACCESS,
  PROT_EXEC                => PAGE_EXECUTE,
  PROT_EXEC | PROT_READ    => PAGE_EXECUTE_READ,
  PROT_EXEC | PROT_READ |
    PROT_WRITE            => PAGE_EXECUTE_READWRITE,
  PROT_EXEC | PROT_READ |
    PROT_WRITE | PROT_COW => PAGE_EXECUTE_WRITECOPY,
  PROT_READ                => PAGE_READONLY,
  PROT_READ | PROT_WRITE   => PAGE_READWRITE,
  PROT_READ | PROT_WRITE |
    PROT_COW              => PAGE_WRITECOPY,
  PROT_WRITE               => PAGE_READWRITE
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(process) ⇒ Memory

Initializes a memory modification instance with the supplied process instance.



51
52
53
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 51

def initialize(process)
  self.process = process
end

Instance Attribute Details

#process ⇒ Object (protected)

:nodoc:



333
334
335
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 333

def process
  @process
end

Instance Method Details

#_allocate(base, length, allocation_type, protection) ⇒ Object

Low-level memory allocation.



80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 80

def _allocate(base, length, allocation_type, protection)
  request = Packet.create_request(COMMAND_ID_STDAPI_SYS_PROCESS_MEMORY_ALLOCATE)

  # Populate the request
  if (base != nil)
    request.add_tlv(TLV_TYPE_BASE_ADDRESS, base)
  end

  request.add_tlv(TLV_TYPE_HANDLE, process.handle)
  request.add_tlv(TLV_TYPE_LENGTH, length)
  request.add_tlv(TLV_TYPE_ALLOCATION_TYPE, allocation_type)
  request.add_tlv(TLV_TYPE_PROTECTION, protection)

  # Transmit the request
  response = process.client.send_request(request);

  return response.get_tlv_value(TLV_TYPE_BASE_ADDRESS)
end

#_free(base) ⇒ Object

Low-level memory deallocation.



109
110
111
112
113
114
115
116
117
118
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 109

def _free(base)
  request = Packet.create_request(COMMAND_ID_STDAPI_SYS_PROCESS_MEMORY_FREE)

  request.add_tlv(TLV_TYPE_HANDLE, process.handle)
  request.add_tlv(TLV_TYPE_BASE_ADDRESS, base)

  process.client.send_request(request)

  return true
end

#allocate(length, protection = nil, base = nil) ⇒ Object

Allocate storage of the supplied length and returns the address at which the memory was allocated.



59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 59

def allocate(length, protection = nil, base = nil)
  allocation_type = MEM_COMMIT

  # If no protection was supplied, default to the most flexible
  if (protection == nil)
    protection = PAGE_EXECUTE_READWRITE
  else
    protection = gen_prot_to_specific(protection)
  end

  # If the preferred base is non-nil, set the reserve flag
  if (base != nil)
    allocation_type |= MEM_RESERVE
  end

  return _allocate(base, length, allocation_type, protection)
end

#free(base) ⇒ Object

Deallocate a region of memory in the context of a process.



102
103
104
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 102

def free(base)
  return _free(base)
end

#gen_prot_to_specific(prot) ⇒ Object (protected)

Translates general protection flags to specific protection flags.



313
314
315
316
317
318
319
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 313

def gen_prot_to_specific(prot)
  if (prot == nil)
    return PAGE_READ
  end

  return @@page_protection_map[prot]
end

#lock(base, length) ⇒ Object

Lock a region of memory into physical memory so that it can’t be swapped to disk. This can only be done in the context of the process that is running the meterpreter server. The instance’s handle is ignored.



233
234
235
236
237
238
239
240
241
242
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 233

def lock(base, length)
  request = Packet.create_request(COMMAND_ID_STDAPI_SYS_PROCESS_MEMORY_LOCK)

  request.add_tlv(TLV_TYPE_BASE_ADDRESS, base)
  request.add_tlv(TLV_TYPE_LENGTH, length)

  process.client.send_request(request)

  return true
end

#protect(base, length = nil, protection = nil) ⇒ Object

Change the protection masks on the region supplied in base.



201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 201

def protect(base, length = nil, protection = nil)
  request = Packet.create_request(COMMAND_ID_STDAPI_SYS_PROCESS_MEMORY_PROTECT)

  if (length == nil)
    length = 4096
  end

  # If no protection was supplied, default to the most flexible
  if (protection == nil)
    protection = PAGE_EXECUTE_READWRITE
  else
    protection = gen_prot_to_specific(protection)
  end

  request.add_tlv(TLV_TYPE_HANDLE, process.handle)
  request.add_tlv(TLV_TYPE_BASE_ADDRESS, base)
  request.add_tlv(TLV_TYPE_LENGTH, length)
  request.add_tlv(TLV_TYPE_PROTECTION, protection)

  # Send the request
  response = process.client.send_request(request)

  # Return the old protection to the caller
  return specific_prot_to_gen(response.get_tlv_value(TLV_TYPE_PROTECTION))
end

#query(base) ⇒ Object

Queries an address for information about its state.



154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 154

def query(base)
  request = Packet.create_request(COMMAND_ID_STDAPI_SYS_PROCESS_MEMORY_QUERY)

  request.add_tlv(TLV_TYPE_HANDLE, process.handle)
  request.add_tlv(TLV_TYPE_BASE_ADDRESS, base)

  response = process.client.send_request(request)

  # Build out the hash from the response information
  info = {}

  info['BaseAddress']       = response.get_tlv_value(TLV_TYPE_BASE_ADDRESS)
  info['AllocationBase']    = response.get_tlv_value(TLV_TYPE_ALLOC_BASE_ADDRESS)
  info['AllocationProtect'] = specific_prot_to_gen(response.get_tlv_value(TLV_TYPE_ALLOC_PROTECTION))
  info['RegionSize']        = response.get_tlv_value(TLV_TYPE_LENGTH)

  # Translate the memory state
  state = response.get_tlv_value(TLV_TYPE_MEMORY_STATE)

  if (state == MEM_FREE)
    info['Available'] = true
  elsif (state == MEM_COMMIT)
    info['Available'] = false
  elsif (state == MEM_RESERVE)
    info['Reserved'] = true
  end

  # Translate the region protections
  info['Protect'] = specific_prot_to_gen(response.get_tlv_value(TLV_TYPE_PROTECTION))

  # Translate the memory type
  type = response.get_tlv_value(TLV_TYPE_MEMORY_TYPE)

  if (type == MEM_IMAGE)
    info['ImageMapping'] = true
  elsif (type == MEM_MAPPED)
    info['MemoryMapping'] = true
  elsif (type == MEM_PRIVATE)
    info['PrivateMapping'] = true
  end

  return info
end

#read(base, length) ⇒ Object

Read memory from the context of a process and return the buffer.



123
124
125
126
127
128
129
130
131
132
133
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 123

def read(base, length)
  request = Packet.create_request(COMMAND_ID_STDAPI_SYS_PROCESS_MEMORY_READ)

  request.add_tlv(TLV_TYPE_HANDLE, process.handle)
  request.add_tlv(TLV_TYPE_BASE_ADDRESS, base)
  request.add_tlv(TLV_TYPE_LENGTH, length)

  response = process.client.send_request(request)

  return response.get_tlv_value(TLV_TYPE_PROCESS_MEMORY)
end

#readable?(base) ⇒ Boolean

Check to see if an address is readable.

Returns:

  • (Boolean) 


271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 271

def readable?(base)
  info = nil

  begin
    info = query(base)
  rescue
  end

  if ((info != nil) &&
      (info['Available'] == false) &&
      (info['Protect'] & PROT_READ == PROT_READ))
    return true
  end

  return false
end

#specific_prot_to_gen(prot) ⇒ Object (protected)

Translates specific protection flags to general protection flags.



324
325
326
327
328
329
330
331
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 324

def specific_prot_to_gen(prot)

  if (prot == nil)
    return PAGE_READONLY
  end

  return @@page_protection_map.invert[prot]
end

#unlock(base, length) ⇒ Object

Unlock a region of memory into physical memory so that it can be swapped to disk. This can only be done in the context of the process that is running the meterpreter server. The instance’s handle is ignored.



250
251
252
253
254
255
256
257
258
259
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 250

def unlock(base, length)
  request = Packet.create_request(COMMAND_ID_STDAPI_SYS_PROCESS_MEMORY_UNLOCK)

  request.add_tlv(TLV_TYPE_BASE_ADDRESS, base)
  request.add_tlv(TLV_TYPE_LENGTH, length)

  process.client.send_request(request)

  return true
end

#writable?(base) ⇒ Boolean

Check to see if an address is writable.

Returns:

  • (Boolean) 


291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 291

def writable?(base)
  info = nil

  begin
    info = query(base)
  rescue
  end

  if ((info != nil) &&
      (info['Available'] == false) &&
      (info['Protect'] & PROT_WRITE == PROT_WRITE))
    return true
  end

  return false
end

#write(base, data) ⇒ Object

Write memory to the context of a process and return the number of bytes actually written.



139
140
141
142
143
144
145
146
147
148
149
 
# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 139

def write(base, data)
  request = Packet.create_request(COMMAND_ID_STDAPI_SYS_PROCESS_MEMORY_WRITE)

  request.add_tlv(TLV_TYPE_HANDLE, process.handle)
  request.add_tlv(TLV_TYPE_BASE_ADDRESS, base)
  request.add_tlv(TLV_TYPE_PROCESS_MEMORY, data)

  response = process.client.send_request(request)

  return response.get_tlv_value(TLV_TYPE_LENGTH)
end