Server hardening is the process of enhancing the security of a server or computer system by reducing its attack surface and limiting the potential vulnerabilities that could be exploited by attackers. This involves implementing various security measures and best practices to safeguard against unauthorized access, data theft, and other malicious activities.
Server hardening is basically securing a server by using advanced security measures at the hardware, firmware and software layers. Hardening can be done on different levels, from the physical level, by restricting the access of unauthorized people, to the application level, by removing unwanted software listening on incoming connections.
Different levels of security provided by Server Hardening:
- Physical Security
- Securing Server Room
- Restricting Access to Server
- Securing Server Hardware
- Operating System Security
- Disabling Unnecessary Services
- Applying Operating System Patches
- Configuring Firewall Rules
- Application System Security
- Securing Web Applications
- Securing Database Applications
- Configuring Application Firewall
- Network Security
- Network Segmentation
- Securing Network Services
- Implementing Intrusion Detection System
- Backup and recovery
- Implementing Backup Policies
- Testing Backup and Recovery Procedures
- Securing Backup Data
Server Hardening Techniques:
- Disabling unnecessary services and ports
- Regularly applying security patches and updates
- Implementing access controls and strong authentication mechanisms
- Configuring firewalls and intrusion detection systems
- Encrypting sensitive data
- Enforcing password policies
- Regularly backing up data to ensure its availability in case of a security incident.
Main Threats:
- Default passwords – Attackers can leverage automated password crackers to guess the defaults. The attack surface this presents could be large if the same defaults are used across many different endpoints–from desktops to IoT–or accounts.
- Hardcoded passwords and other credentials stored in plain text files can increase the attack surface in a couple important ways. If they are forgotten in deployed code or otherwise publicly exposed, the hardcoded credentials can provide a backdoor into the organization.
- Unpatched software and firmware vulnerabilities are historically one of the biggest contributors to attack surfaces. While patching will mitigate a vulnerability, patches are not always available as in the case of zero day threats. Moreover, some patches may be too disruptive to implement or not economically feasible.
- Unencrypted, or inadequately encrypted, network traffic or data at rest can make it easy for attackers to access data or eavesdrop on conversations and access and potentially gain important information (such as passwords) needed to advance an attack.