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.
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.
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:
It includes the tracking of process and sub-processes flow in real time.
Centralized control enables the organizations to control, deploy and distribute all their servers in just a single click easily.
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.
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.