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.
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
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.
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.