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.


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

def initialize(process)
  self.process = process
end

Instance Attribute Details

#processObject (protected)

:nodoc:


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

def process
  @process
end

Instance Method Details

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

Low-level memory allocation.


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# 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, length) ⇒ Object

Low-level memory deallocation.


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# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 109

def _free(base, length)
  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)
  request.add_tlv(TLV_TYPE_LENGTH, length)

  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.


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# 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, length = 0) ⇒ Object

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


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

def free(base, length = 0)
  return _free(base, length)
end

#gen_prot_to_specific(prot) ⇒ Object (protected)

Translates general protection flags to specific protection flags.


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# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 314

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.


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# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 234

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.


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# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 202

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.


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# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 155

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.


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# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 124

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)

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# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 272

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.


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# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 325

def specific_prot_to_gen(prot)

  if (prot == nil)
    return PAGE_READONLY
  end

  return @@page_protection_map.invert[prot]
end

#unlock(base, length) ⇒ Object

Unloock 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.


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# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 251

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)

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# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 292

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.


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# File 'lib/rex/post/meterpreter/extensions/stdapi/sys/process_subsystem/memory.rb', line 140

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