🧱🔥The Hidden Risk of Internet-Facing Firewall Management Interfaces🧨

Firewalls are a cornerstone of modern business security, protecting networks from malicious threats and unauthorised access. However, when the management interfaces of firewalls such as Fortinet and Palo Alto are exposed to public Internet links, they become significant security risks. The persistent exploitation of these interfaces has led to a series of high-profile breaches, most recently involving Fortinet firewalls. This is not an isolated incident but part of a worrying trend that is unlikely to end.

The solution to this risk lies in implementing an Out-of-Band (OOB) management network, which eliminates the need to expose firewall management interfaces to the public Internet. This article explores how OOB networks work, why they are critical, and how modern solutions like Teltonika hardware and services like ionline’s private APN can provide secure and efficient OOB management.

Understanding Out-of-Band (OOB) Networks

An Out-of-Band network is a separate, isolated network dedicated to the management and monitoring of critical IT infrastructure. Unlike standard in-band management, which shares the same network as regular business traffic, OOB management is completely segregated. This separation ensures that management traffic is not exposed to the same risks as public-facing traffic, providing a secure pathway for administrators to monitor and control devices.

By routing management traffic through an OOB network, businesses can:

• Eliminate exposure: The management interface of the firewall is no longer directly accessible via the public Internet, significantly reducing the attack surface.

• Ensure continuity: An OOB network remains operational even if the primary network fails, enabling critical troubleshooting and recovery.

• Control access: Access to the OOB network can be tightly controlled and monitored, further enhancing security.

Using Cellular Networks for OOB Management

A practical implementation of an OOB network is leveraging cellular networks through a router or modem. By using a private Access Point Name (APN), businesses can create a dedicated, secure channel for OOB management.

What is a Private APN?

A private APN is a customised configuration of a mobile network’s gateway that provides private, secure connectivity to authorised devices. Unlike public APNs, which allow Internet access for general users, a private APN creates a closed-loop network. Key features include:

• Exclusive access: Only authorised devices can connect to the network.

• Custom routing: Traffic can be routed to specific destinations, such as an OOB management server.

• Enhanced security: Data does not traverse the public Internet, minimising exposure to threats.

Implementation with Teltonika and ionline

Teltonika routers, combined with ionline’s private APN service, provide an excellent solution for OOB management. Here’s how it works:

1. Hardware Setup: A Teltonika router is configured to connect to a private APN provided by ionline.

2. Network Isolation: The firewall’s management interface is moved off the public Internet and onto the OOB network.

3. Controlled Access: Only authorised personnel can access the management interface through the OOB network.

4. Bandwidth Optimisation: ionline’s service includes features to block non-essential traffic, such as social media, ensuring that bandwidth is reserved for business-critical tasks.

In addition to secure management, the OOB network can serve as a failover connection. If the primary fibre or fixed wireless link fails, the cellular OOB network ensures continued connectivity.

SD-WAN Integration with Fusion

For small businesses leveraging SD-WAN, Fusion offers a unique solution. Fusion’s SD-WAN platform includes a built-in OOB management plane by default. This architecture supports firewall functionality on its NFV (Network Function Virtualisation) edge devices, which are compatible with:

• Clavister

• WatchGuard

• pfSense

• OPNsense

• OpenWrt

• Special cases: Mikrotik

By isolating the management plane, Fusion provides an industry-leading level of security. The OOB management interface is never Internet-facing, reducing risks and aligning with best practices.

Why OOB Networks Are Essential for Modern Businesses

Public-facing management interfaces are a ticking time bomb for any organisation. The recent wave of exploits targeting Fortinet firewalls underscores the need for proactive measures. By implementing an OOB network, businesses can:

• Mitigate Risk: Remove public exposure of management interfaces.

• Enhance Security: Use private APNs to safeguard management traffic.

• Improve Resilience: Maintain management capabilities during network outages.

• Boost Efficiency: Block non-essential traffic and prioritise business-critical systems.

Wrap

The persistent exploitation of firewalls’ public-facing management interfaces is a stark reminder of the importance of secure management practices. Implementing an OOB network using solutions like Teltonika hardware and ionline’s private APN service provides a robust defence against these risks. For small businesses, Fusion’s SD-WAN platform offers an advanced and secure deployment, ensuring that firewall management is never a vulnerability.

By prioritising OOB management, businesses can protect their networks, ensure continuity, and maintain control in an increasingly hostile cybersecurity landscape.

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