Security Advisory: Multiple Vulnerabilities in NetModule Routers

Introduction

This is the third security advisory we release in cooperation with ONEKEY that is related to the introduction of a “zero-day identification” module that performs static code analysis on proprietary applications found within firmware uploaded to ONEKEY’s platform.

NetModule is an Original Equipment Manufacturer of industrial grade routers. The vulnerabilities identified within the web management interface allow authenticated users to execute arbitrary commands with elevated privileges or to access any file on the system.

These vulnerabilities were automatically identified by our platform during one of those industrial routers’ firmware scan:

All our findings were validated using an emulated device and reported to NetModule, whose PSIRT team confirmed our findings. 

Authenticated Command Injection

Summary

The NetModule web administration interface executes an OS command constructed with unsanitized user input.

Impact

A successful exploit could allow an authenticated user to execute arbitrary commands with elevated privileges.

Description

The NetModule Router Software web admin interface is written in PHP and has a page allowing for GNSS receiver configuration at /home/www-data/admin/gnssAutoAlign.php .

On line 36, the script calls exec with an unsanitized $device_id variable obtained from the POST request on line 6:

<?php
require_once('config/config.php');
if (isset($c))
   $device_id = $c;
else
   $device_id = $_REQUEST['device_id'];
$status = "disabled";
define("STATUS_FILENAME", "/tmp/status/gnss". $device_id ."/dr-auto-align");
define("ANGLES_FILENAME", "/tmp/status/gnss". $device_id ."/dr-auto-align-angles");
define("PID_FILENAME", "/run/gnss". $device_id ."/dr-auto-align.pid");

if (file_exists(STATUS_FILENAME)) {
   $statusfile = fopen(STATUS_FILENAME,"r");
   $status = fread($statusfile, filesize(STATUS_FILENAME));
   fclose($statusfile);

}
$yaw = "n/a";
$pitch = "n/a";
$roll = "n/a";

if (file_exists(ANGLES_FILENAME)) {
   $anglesfile = fopen(ANGLES_FILENAME,"r");
   $angles = fread($anglesfile, filesize(ANGLES_FILENAME));
   fclose($anglesfile);


   $angles = explode("\n", $angles);
   $yaw = explode("yaw: ", $angles[0])[1];
   $pitch = explode("pitch: ", $angles[1])[1];
   $roll = explode("roll: ", $angles[2])[1];
}


if (isset($_POST['toggleAlignment'])) {
    if ($status == "disabled") {
        exec("/usr/local/sbin/www-scripts/various/doAutoAlignment " . $device_id . " >
/dev/null &");
        $status = "starting";
}
    else {
        exec("kill $(cat ". PID_FILENAME . ")");
        $status = "stopping";
    }
}

 

Authenticated Path Traversal

Summary

The NetModule web administration interface is vulnerable to path traversals, which could lead to arbitrary file uploads and deletion.

Impact

By uploading a malicious PHP file within the web administration root directory, an authenticated user could gain unconstrained remote command execution.

Description

The NetModule Router Software web admin interface is written in PHP and has a page to handle what they call “SDK jobs” at /home/www-data/admin/include/sdkJobs.php. This script calls move_uploaded_file on line 320 with unsanitized user input:

if (!move_uploaded_file($_FILES["scriptUpload"]["tmp_name"],$uploadpath))

The unsanitized user input is constructed this way:

$name = trim($_POST['scriptName']);
$uploadpath = UPLOAD_DIR ."/" . $name;

Key Takeaways

Obviously, updates need to be installed to resolve the reported vulnerabilities. But although prior authentication is required to exploit this vulnerability, this issue serves as an example of a mission-critical device being shipped with high-risk vulnerabilities. Ideally, such issues would be discovered during the vendor’s quality assurance processes, but operators of critical infrastructure in particular must practice due diligence. In this writeup, we demonstrate that this does not always need to be a manual test but that the better part of such an assessment can be automated.

Timeline

2022-09-20 – Sent coordinated disclosure request to support@netmodule.com

2022-09-20 – Answer from NetModule Support, establishment of secure communication channel and report sent out.

2022-10-17 – First feedback from NetModule dev team. 

2022-11-15 – Coordination between NetModule and ONEKEY on firmware release planning. 

2022-11-28 – NetModule releases fixed firmware for supported branches. ONEKEY and NetModule agree on embargo on publication to allow for NetModule clients to apply patches

2023-02-24 – ONEKEY & CERTAINITY releases its advisory