Two Factor Authentication – Best for the UNIX/Linux Server Security

The UNIX/Linux server security is challenging, because these servers are at a risk of getting compromised at any point of time by the attackers. In today’s enterprise environment, the UNIX and Linux servers are growing popular. With their increased popularity, these servers have become the primary target of the attackers for security breaches. There have been numerous cases of harmful external security threats where the attackers have gained access to these servers; UNIX and Linux, through the Internet. The largest security threat to UNIX/Linux server is internal, not external. Therefore, it is must for the enterprises to improve their UNIX/Linux server security, so that comprising server becomes complicated for the hackers.

UNIX is used by 66.5 percent of all the websites whose operating system we know.

Internal security threats can come from anywhere & anytime. In UNIX/Linux servers, some of these threats that are common and extremely harmful include the following:

  • Backdoor created by a user.
  • Account duplicated by a privileged user.
  • A piece of code implanted by the system administrator or developer that may damage the server.

Security breaches – The big problem

With security breaches on the rise at an alarming rate, the UNIX/Linux server security is becoming more challenging and necessary for the system administrators. For gaining access to a server, most of the system admins worldwide rely on just a single authentication factor, i.e. the password. But, hackers or the online attackers use brute force or several other proven methods that help break password of the server and gain access to it. Therefore, it is must for the system admins to use more than just password-alone verification for optimal UNIX/Linux server security against all sorts of harmful internal or external security threats.

The solution to these threats

Adding an additional verification step in the login process is must for protecting the servers; UNIX and Linux, against security threats. One ideal & proven solution that ensures a high security level is Two Factor Authentication. The system admins must implement this solution and experience the peak security they are looking for.

An overview

Two Factor Authentication (2FA) is an authentication method that adds an additional security layer for verifying identity of a admin and completing the login procedure successfully. 2FA security solution requires two independent factors or pieces of information – password and a verification code, to verify identity and privileges of the system admin. This security method is stronger as well as more rigorous than the normal password-alone verification that requires only one factor, i.e. the admin’s password. 2FA is also referred to as Two Step Verification method.

The system admin knows the password (the first factor), and verification code (the second factor) is sent to his registered physical device. This verification code is valid only for a few seconds. If any hacker manages to get the password, then he needs the second authentication factor; verification code, to prove his identity and access UNIX/Linux server completely. In this way, Two Factor Authentication solution ensures UNIX/Linux server security at its peak.

Authentication factors used in 2FA

Below are the possible authentication factors used in 2FA security solution:

  • The knowledge factors (something you know) – username, password, PIN, any other secret information, i.e. question & answer.
  • The possession factors (something you have) – security token, any physical device to receive the code.
  • The inherence factors (something you are) – biometric characteristics such as iris, retina, face scan, voice recognition, fingerprint.
  • Time and Location factors (geolocation).

Two Factor Authentication, as its name suggests, uses any two of the above-listed authentication factors to verify identity of the system administrator. Without the combination of any two of these verification factors, the system admin won’t be able to gain access.

2FA benefits

Some major benefits of Two Factor Authentication security solution are:

  • Greatly enhances the security level by requiring two different pieces of information or factors for authentication.
  • Reduces the security risk associated with the weak passwords that can be easily cracked.
  • Provides an alert in the form of a second factor; verification code, whenever any unauthentic user enters the valid password.

UNIX/Linux server security monitoring

The monitoring includes process activities and behaviour for detecting loopholes. This process helps to provide a unique view of the flow of commands running inside the UNIX/Linux session.

Benefits associated with monitoring are:

Process-based Inspection

It includes the tracking of process and sub-processes flow in real time.

Centralized Management

Centralized control enables the organizations to control, deploy and distribute all their servers in just a single click easily.

Real-time Alert

In case of any security violation like package installations, use of unexpected commands, etc., the real-time activity alert will help the system admin to take some security measures for a better protection.

User Activity Inspection

Any sort of illegitimate tasks that may compromise the UNIX/Linux server security can be monitored.

Intrusion Detection

Inspecting the processes or activities that play a pivotal role in hacking the servers.

What are the best practices for controlling UNIX/Linux account privileges?

Below are these best practices:

Managing UNIX/Linux Accounts

Account creation is an easy task, but disabling or removing unrequired accounts is quite complex for the system administrators. They (admins) must actively manage the accounts for minimizing the security risk to server and enterprise.

Implement Least Privilege

The principle of least privileges is one of the best practices from UNIX/Linux server security point of view. For controlling internal threats, restricting the rights and access of a user to the minimal amount is an important practice.

Minimize the Shared Accounts Use

The system administrators should not share accounts. Limit the application’s privilege on the system.

Notify Malicious Activities

After establishing and implementing logging and audit system, the system administrators must set up automated notification of all the malicious activities. Every major and minor violation needs to be reported by the system admins for a better UNIX/Linux server security against all sorts of the intrusions. In fact, alerting and notification system makes the system admins proactive rather than reactive.

Always remember that a good privileged plan is a key to the UNIX/Linux server security at every step.

Get Assured Linux Server Security With 2FA Solution

Linux server security is a challenging task for the enterprises, but it’s highly necessary in today’s frequently occurring malicious attacks. As per a report given by The Linux Foundation, Linux is leading Windows on both the deployments, i.e. cloud and enterprise application.

Below are a few stats:

Linux application deployments have risen from 65% to 79%.

Linux is used by 37.2% of all the websites whose operating system we know.

After creating a Linux cloud server, the first and the most important step should be to set the security on it. The system administrator must perform this crucial step to prevent the fraudsters or hackers from gaining access to your Linux server. It not only results in a more secure environment, optimal Linux server security, but also prevents your business from being hacked. Hardening the security level on your Linux server will make the hackers frustrated, as they won’t be able to gain access. So, it’s better to use the latest tips or methods for improving the security.

The system administrators have all the privileges or access rights to log in to a Linux server. By default, the login credentials required to access a Linux server are: IP address, or you can say username or server name, and password combination. If an attacker gets these credentials, then he can easily log in to your Linux server, and experience the same privileges like the system administrator. It reflects that accessing the server using just a single protection layer, i.e. the password, may results in hacking. Therefore, adding an extra security step in the login procedure is must for top level Linux server security. 2FA seems an ideal solution for securing the Linux servers against external threats and security breaches.

2FA definition and how does it work

2FA (Two Factor Authentication) is a security process that adds an additional protection layer in the login procedure to verify whether the user who is logging is authentic or not. This security process requires two different factors – password and a verification code for a successful login. Every authentic user knows the first factor, i.e. password, and the second factor, i.e. verification code is sent to his registered device immediately after entering the valid login credentials. The verification code is valid only for a few seconds. 2FA is also referred to as Two Step Verification method.

With 2FA, an additional security layer is added which makes it a complicated task for an attacker to login even if he gets the password. It is because the password alone is not enough to pass the authentication check. Two Factor Authentication has been proved to be a powerful security solution for controlling access to sensitive systems and data. In fact, 2FA prevents the enterprises’ servers and other confidential data from being hacked by the hackers who have stolen the passwords.

Two Factor Authentication requires not only a password, but also something that only the user has with him, i.e. a physical device. Knowing the password and having access to the user’s device seems not so easy for an attacker. Therefore, 2FA provides better protection against all sorts of security breaches.

One of the most common examples of 2FA security method is cash withdrawal through an ATM using your credit/debit card. For withdrawing cash successfully, you need both card and a 4-digit PIN. Without the combination of both card and a PIN, cash withdrawal won’t be possible even if you are a real user of the card. This is an offline example of Two Factor Authentication.

In the same way, if an intruder steals your password, then he needs access to your physical device as well for hacking the system completely. Due to the use of two different and independent authentication factors to log in to the online system, 2FA solution ensures unmatched Linux server security.

What are authentication factors?

The ways in which someone can be authenticated are known as the authentication factors. These factors usually fall into five categories that have been shown below:

The knowledge factors (something the user knows) – username, email id, password, PIN, a secret question & its answer.

The possession factors (something the user has) – any physical device to receive verification code; the second factor.

The inherence factor (something the user is) – biometric characteristics such as iris, retina, face scan, voice recognition, fingerprint.

Time factors

Location factors – includes geolocation.

Two Factor Authentication, as the name suggests, includes any two of the above-listed authentication factors. On the other hand, MFA (Multi Factor Authentication) includes more than two independent credentials for securing the online transactions.

Some additional Linux server security strengthening tips

User Management

By default, the root user is created as the first user on every Linux system, and should be used only for the initial configuration of the system. The root user should be disabled via SSH (Secure Shell or Secure Socket Shell). Disabling this root user via Secure Shell makes it harder for an intruder to log in to the system. It is because the root user is created by default on every Linux server, if this user is enabled via SSH, then the hackers already have half the information they need to log in to your server. The hackers just need to run brute force SSH attack until the password is broken.

The best solution to avoid this situation is to create a secondary user to log in and administer the system.

Strong Passwords

The system administrator must create strong passwords that contain uppercase & lowercase letters, numbers and special characters & symbols. Apart from this, enforce password ageing, so that changing password at regular time intervals becomes must. The number of failed login attempts should not be more than 3.

Use Intrusion Detection Systems

Install both NIDS (Network Intrusion Detection System) and HIDS (Host-based IDS). NIDSs are used to protect against malicious threats. HIDSs are used to monitor file system changes. They (HIDSs) produce a report that tells you which files have been modified, so that you can repair or replace them.

Secure Linux Kernel

Modify the /etc/sysctl.conf file to secure your Linux Kernel. The Kernel reads this file at boot time.

Install Linux Kernel Patches

You should have a written security policy for handling Linux Kernel Patches. This policy includes which Linux security notices have been received, which updates have been tested to ensure problems don’t arise and which patches have been installed on the system. Always ensure Production servers are updated regularly to avoid any potential known vulnerability from being exploited on your system.

Stay one step ahead of the intruders, and enable proven security solution to get unmatched Linux server security at every step. Follow the above-listed tips for better protection against security breaches.