Talos Vulnerability Report

Summary

An OS command injection vulnerability exists in the console infactory_wlan functionality of InHand Networks InRouter302 V3.5.37. A specially-crafted series of network requests can lead to remote code execution. An attacker can send a sequence of requests to trigger this vulnerability.

Tested Versions

InHand Networks InRouter302 V3.5.37

Product URLs

InRouter302 - https://www.inhandnetworks.com/products/inrouter300.html

CVSSv3 Score

9.9 - CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CWE

CWE-78 - Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’)

Details

The InRouter302 is an industrial LTE router. It features remote management functionalities and several security protection mechanism, such as: VPN technologies, firewall functionalities, authorization management and several other features.

The InRouter302 offers telnet and sshd services. Both, when provided with the correct credentials, will allow access to the Router console.

Here is the prompt after the login:

************************************************
        Welcome to Router console
    Inhand
    Copyright @2001-2020, Beijing InHand Networks Co., Ltd.
    http://www.inhandnetworks.com
------------------------------------------------
Model                : IR302-WLAN
Serial Number        : RF3022141057203
Description          : www.inhandnetworks.com
Current Version      : V3.5.37
Current Bootloader Version : 1.1.3.r4955
------------------------------------------------
get help for commands
------------------------------------------------
type '?' for detail help at any point
================================================
help           -- get help for commands
language       -- Set language
show           -- show system information
exit           -- exit current mode/console
ping           -- ping test
comredirect    -- COM redirector
telnet         -- telnet to a host
traceroute     -- trace route to a host
enable         -- turn on privileged commands
infactory      -- factory mode
Router>

The infactory command permits, provided the correct password, the access to the factory mode view. This mode permits to change some configuration and performs various tests. The factory mode view:

Router> infactory 
input password: 
Router(factory)# 
get help for commands
------------------------------------------------
type '?' for detail help at any point
================================================
help           -- get help for commands
language       -- Set language
exit           -- exit current mode/console
reboot         -- reboot system
factory-model  -- hardware model configure
modem          -- modem test
reset-key      -- check the status of the reset button
com            -- detecting serial ports
port           -- FCT network port test
net            -- complete machine network port test
led            -- LED lights test
wlan           -- Wi-Fi test
mem            -- check memory
hw_wdg         -- check the hardware watchdog status
dio            -- detect digital I/O
stategridsec   -- detect stategrid security chip
Router(factory)# 

This mode offers several functionalities. For instance, the wlan functionality allows to set the SSID on a specific network interface.

The wlan_functionality:

undefined4 wlan_functionality(undefined4 param_1,char *args)

{
[...]

command_list[0] = args;
[...]
if (command_list[0] != (char *)0x0) {
    first_arg = (char *)get_next_token(command_list);
    if ((*first_arg != '\0') && (second_arg = (char *)get_next_token(command_list), *second_arg != '\0')) {
    is_2g = strncmp(first_arg,"2g",2);
    if (is_2g == 0) {
        [... perform a setup ...]
        is_status = strncmp(second_arg,"status",6);
        if (is_status == 0) {
            [...]
        }
        is_connect = strncmp(second_arg,"connect",7);
        if (is_connect == 0) {
        if (((command_list[0] != (char *)0x0) && (*command_list[0] != '\0')) &&
            (third_arg = (char *)get_next_token(command_list), *third_arg != '\0')) {                   [1]
            [...]
            snprintf(&set_SSID_string,0x80,"iwpriv %s set SSID=\"%s\"",&interface_name,third_arg);      [2]
            system(&set_SSID_string);                                                                   [3]
            [...]
}

If the first and second provided arguments are 2g and connect, then the third one, parsed at [1], will be later used at [2] to form the string iwpriv <interface> set SSID="<third_arg>". This string will be later used at [3] as argument of the system function.

The third argument is not properly sanitized, and a command injection can occur at [3]. An attacker, able to reach the wlan functionality, would be able to obtain a root shell.

Exploit Proof of Concept

Provided the command wlan 2g connect ;$(reboot), in the factory mode view, the device will reboot.

Vendor Response

The vendor has updated their website and uploaded the latest firmware on it. https://inhandnetworks.com/product-security-advisories.html https://www.inhandnetworks.com/products/inrouter300.html#link4

https://www.inhandnetworks.com/upload/attachment/202205/10/InHand-PSA-2022-01.pdf

Timeline

2022-03-30 - Vendor Disclosure
2022-05-10 - Public Release
2022-05-10 - Vendor Patch Release