Exploit-DB #15241
Description: Oracle Java 6 - OBJECT tag 'launchjnlp'/'docbase' Remote Buffer Overflow
Type: remote
Platform: windows
Date: 2010-10-13
Author: Skylined

Exploit:
Source:  http://code.google.com/p/skylined/issues/detail?id=23

SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS
                                                                                                                        
   ,dSSSSSSSSSSSS  SSSS    ,dSSY'  SSSS      SSSS  SSSS          SSSS  SSSSb,    SSSS  ,dSSSSSSSSSSSS  SSSSSSSSSSSSb,   
   SSSS            SSSS  ,dSSY'    SSSS      SSSS  SSSS          SSSS  SSSSSSb,  SSSS  SSSS            SSSS      SSSS   
   'YSSSSSSSSSSb,  SSSSSSSSSSSSb,  'YSSSSSSSSSSSS  SSSS          SSSS  SSSS'YSSb,SSSS  SSSSSSSSSSS     SSSS      SSSS   
             SSSS  SSSS      SSSS            SSSS  SSSS          SSSS  SSSS  'YSSSSSS  SSSS            SSSS      SSSS   
   SSSSSSSSSSSSP'  SSSS      SSSS  SSSSSSSSSSSSP'  'YSSSSSSSSSS  SSSS  SSSS    'YSSSS  'YSSSSSSSSSSSS  SSSS  SSSSSSP'   
                                                                                                                        
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS
                                                                                                                        
 Internet Exploiter 12+DEP: Oracle Java 6 OBJECT tag "launchjnlp"/"docbase" param buffer overflow exploit.              
 Copyright (c) 2010 Berend-Jan "SkyLined" Wever <berendjanwever@gmail.com>                                              
 All rights reserved. This information is provided for academic purpose only.                                           
                                                                                                                        
 This exploit targets a stack based buffer overflow in Oracle Java 6. The vulnerability has been confirmed in Update 20 
 and 21 and it probably exists in earlier version as well. The overflow allows control over the EBP and EIP registers   
 when the vulnerable code returns.                                                                                      
                                                                                                                        
 This exploit tries to bypasss DEP using the "Havoc" mechanism first published at                                       
 http://skypher.com/index.php/2010/03/01/internet-exploiter-2-dep/. This is a combination of a heap spray and a         
 ret-into-libc attack that tries to set the executable flag on a block of memory in the heap spray before executing it. 
                                                                                                                        
 After setting up the heap spray, the stack overflow in Java is used to overwrite EBP and EIP. EIP is pointed to any    
 LEAVE, RET instruction sequence in the code section of any loaded module at an address that can be encoded in the      
 buffer overflow string (characters [\x00\x80-\x9F] cannot be used!) The LEAVE instruction provides control over ESP,   
 which makes the ret-into-libc attack possible.                                                                         
 The ret-into-libc attack causes consecutive calls to ZwProtectVirtualMemory in ntdll. Each call tries to change the    
 memory protection flags for a memory region that should be covered by the heap spray and contain the shellcode.        
 Multiple calls are needed because the base address of the memory block that contains the shellcode is not know. One    
 call is made for each possible value, and therefore all but one of these calls should fail. After these calls, the     
 ret-into-lic stack returns to the shellcode, which by now should be executable because of the one call to              
 ZwProtectVirtualMemory that succeeded.                                                                                 
                                                                                                                        
 This exploit does not attempt to bypass ASLR. When testing on a target with ASLR enabled, you can provide the base     
 address of ntdll by appending "?iNtDllImageBase=0xXXXXXXXX" tot the url. Alternatively, you could try to find a way to 
 determine the base address of ntdll automatically or do a brute-force attack that tries all ~256 possible values       
 (hint, hint :D).                                                                                                       
                                                                                                                        
 This exploit has been tested succcessfully on Windows XP sp3 en-us (x86), Windows Vista sp2 en-us (x86) and Windows 7  
 en-us (x64) and with MSIE 6.0, 7.0 and 8.0 using Java 6 Update 21.                                                     
                                                                                                                        
 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the       
 following conditions are met:                                                                                          
    * Redistributions of source code must retain the above copyright notice, this list of conditions and the following  
      disclaimer.                                                                                                       
    * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the         
      following disclaimer in the documentation and/or other materials provided with the distribution.                  
    * Neither the name of the copyright holder nor the names of the contributors may be used to endorse or promote      
      products derived from this software without specific prior written permission.