Linux is secure by default, and has in-built security model in place. To make it (Linux) a more secure system, you need to customize it as per your requirements. Linux offers more flexibility and configuration options. Securing a system from the hackers, wrong hands, or unauthorized access, is a challenging task for the System Administrator.
To make this challenging task easier, several useful tips have been mentioned in this post. So, read it to know those proven tips, and implement them as soon as possible.
Hope, below useful tips & tricks will help you enhance security of Linux servers to a high level:
Physical Server Security
You must protect Linux servers physical console access. Configure the BIOS (Basic Input/Output System) and disable booting from external devices. To restrict physical access of the server, enable BIOS password and protect GRUB (GRand Unified Bootloader) with password.
It is extremely important to have different partitions to obtain higher data security in case if anything wrong happens. By creating different partitions, data can be separated and grouped. When an unexpected accident occurs, only data of that partition will be damaged, while the other will remain safe.
Minimize Packages to Minimize Vulnerability
For better security of the Linux servers, it is recommended to avoid installing useless packages to minimize vulnerabilities in packages. This may minimize risk that lead to compromise of other services. Find and remove or disable unwanted services from the server immediately to minimize vulnerability. Use ‘chkconfig’ command to disable all unwanted network services from the server.
Check Listening Network Ports
With the help of ‘netstat’ networking command, you can view all open ports and associated programs.
Encrypt Data Communication
Encryption is must for establishing a secure data communication. Use SSH (Secure Shell or Secure Socket Shell), a secure protocol, that uses encryption technology during communication with the server.
Use Linux Security Extensions
Linux comes with various security patches which can be used to guard against misconfigured or compromised programs. If possible, use SELinux (Security-Enhanced Linux) and other Linux security extensions to enforce limitations on network and other programs. SELinux provides a variety of security policies for Linux kernel.
Monitor User Activities
If you are dealing with lots of users, then it is important to collect the information of each user activities and processes consumed by them and analyse later or in case of performance and security issues. Both ‘psacct’ and ‘acct’ are useful tools used for monitoring user activities and processes on the Linux server.
Keep Linux Kernel and Software Up to Date
Applying security patches is an important part of maintaining Linux server. Linux provides all necessary tools to keep your system updated, and allows for easy upgrades between versions. All security update should be reviewed and applied as soon as possible.
Review Logs Regularly
Move logs in dedicated log server, this may prevent intruders to easily modify local bugs.
Lock and Unlock Account Manually
The lock and unlock features are very useful, instead of removing an account from the system, you can lock it for a week or a month.
Logging and Auditing
For collecting all hacking and cracking attempts on the Linux server, you need to configure logging and auditing. This is also useful to find out software misconfiguration which may open your system to various attacks.
Implement all the above-listed useful tips for strengthening the security of your Linux servers, and make sure that they don’t get hacked.