Bastion Host: Do you really need this? – GreenCloud

There are several layers of security you can put in place to protect your network from external threats. One such security tool to use is a cloud business VPN, but there are many other options available to cover various attack vectors. You may have read that bastion host is a potential solution to your cyber security risks. However, bastion hosts are outdated technology and will not protect you from all attempts. Knowing what a bastion host is is important to understand why alternative security methods are needed.

What is Bastion Host?

A bastion host is a specialized computer that is deliberately exposed on a public network. From the point of view of a secure network, it is the only node exposed to the outside world and is therefore very vulnerable to attack. It is placed outside the firewall in single firewall systems, or if the system has two firewalls, it is often placed between the two firewalls or on the public side of the demilitarized zone (DMZ).

A bastion host processes and filters all incoming traffic and acts as a gateway to prevent malicious traffic from entering the network. The most common examples are mail, domain name systems, Web, and File Transfer Protocol (FTP) servers. Firewalls and routers can also be bastion hosts.

How does this work?

To understand how Bastion host works, we'll look at a simple scenario where company administrators require access to subnetted Linux instances in a virtual private cloud. In each example, exposing a port to the public Internet will give administrators the access they need. But the security implications make this approach very risky.

Instead, it is used as a bridge between the public Internet and a private subnet. Bastion operates as a locked-down, single-purpose system—in this case, an SSH proxy server. Administrators remove all unnecessary programs, ports, processes, user accounts, and protocols. Anything that does not serve the sole purpose of the bastion host as an SSH proxy is disabled or removed.

The Bastion host resides on its own subnet with an IP address that can be accessed from the public Internet. Bastion only accepts SSH connections from limited IP addresses in the IT department. ACLs, permission lists, and other network-level access controls restrict access from the firewall to its protected subnets.

When authorized users need to access a resource on a private subnet, they must first use SSH keys to connect to the bastion host. Once authenticated, they can use another set of SSH keys to connect to the private network.

Does your business need it?

You have sensitive data stored in your business. This information may include usernames and passwords, credit card numbers, customer details and financial records.

As a business owner, you don't want anyone outside of your company to access these private resources.

To prevent this from happening, a bastion host provides access to your employees but prevents hackers from accessing your data.

Some other reasons you might want to use a bastion host server in your business include:

• Secure remote access: Having remote teams makes your business more vulnerable to attacks. Having a Bastion host protects your private resources and allows employees to access your network remotely.
• Network segmentation: You can segment your private network by isolating it from your external network.
• Registration and monitoring: You can track everyone accessing your resources and monitor everything happening on your network. This includes failed logins that help identify the attack.
• Single entry point: It creates a single point of access that makes it easy to manage who has access to your business resources. This can prevent attackers from gaining access to your entire network once they gain access to one system.
• Hardening: Usually they are fixed. This means they protect against some of the more common attacks and make it harder for attackers to break into your network.

What is the difference between firewall and bastion host

Firewalls and bastion hosts are both security tools, but they serve different purposes:

A firewall acts as a wall that blocks unauthorized traffic based on predefined rules. It's like a castle gatekeeper who decides who gets in based on a set of criteria.

Bastion Host provides controlled access for authorized users through secure channels.

While firewalls block unwanted traffic, bastion hosts provide secure access for authorized users. They work together to create a layered defense system for your network.

What is the difference between VPN and bastion host?

They both provide secure remote access, but their approaches are different:

A VPN creates a secure tunnel between the remote device and the internal network, encrypting all traffic passing through it. It's like a secret pass that gives authorized users direct access to the entire network.

The Bastion host acts as a centralized gateway, controlling and monitoring all remote access from a single point. It acts as a secure checkpoint for authenticated users before granting access to specific resources within the network.

What are the security risks of using Bastion Host?

Like any other technology application, bastion hosts expose organizations to security risks. These risks stem from bastion hosts providing internal access via the Secure Shell Protocol (SSH). SSH is a widely used encryption and authentication method for communication between networks.

Cyber ​​attackers often target it because accessing SSH encryption keys can give them high-level access to a protected network. It's like giving thieves a master key that can open any room in the house. Once attackers have the SSH key, they can bypass the bastion host and access the internal network.

Another risk fortress hosts have is their public visibility. Thus, attackers can easily gain access through brute force attacks where they use trial and error to guess passwords or SSH keys.

The result

Some say that using bastion hosts and switch servers is obsolete. In small IT infrastructures, they are a fair solution for their role if you configure them correctly and enforce security. But you must remember that the owner of the bastion can only do one trick. Act as a gateway between the external and internal network. That's all.

Depending on your company's specific needs, resources, and capabilities, a bastion host can do a good job of protecting access to your private network. You will have to handle it with extra care and pay attention to patches, vulnerability scanning, etc.