The Critical Role of Operating System Patches in Cybersecurity
The Importance of Operating System Patches
Operating system vendors continuously identify and fix flaws in their code, releasing updates known as patches. Regardless of the operating system you use, applying these patches regularly has become essential. While some patches address bugs, others fix security vulnerabilities that can expose your system to cyber threats. Each vulnerability is like an open door, inviting cybercriminals to exploit your system. No matter how robust your security measures are, leaving these doors open puts you at risk. It’s crucial to understand that threats often enter through these vulnerabilities rather than your applications.
Applying Patches to Your Operating System
Applying patches ensures the security of your operating system, database management systems, development tools, web browsers, and more. Keeping all patches up-to-date is a fundamental security practice. In a Microsoft corporate environment, this process is streamlined. When evaluating a system, applying patches should be one of your first tasks. Regardless of the operating system or application vendor, you should be able to visit their website and find instructions on downloading and installing the latest patches.
Remember, everything needs patching. This includes the operating system, applications, drivers, and network hardware like switches and routers. After ensuring all patches are up-to-date, the next step is to establish a system to maintain this status. A simple method is to initiate periodic patch reviews where all machines are checked for patches at a specific time. Alternatively, you can use automatic solutions to patch all systems in your organization.
Automatic Patch Systems
Manual patching is cumbersome and impractical for larger networks. However, you can find automatic solutions that patch all systems on your network. These solutions scan your systems at predetermined times and apply the necessary patches automatically. For systems running Microsoft Windows, you can set your system to patch automatically. In the latest versions of Windows, this feature is enabled by default.
This approach has some drawbacks. First, it only updates Windows, not other applications on your machine. Second, it may introduce issues if you don’t test the updates before deploying them across your entire network. The main advantages are that it’s free and integrated with the Windows operating system. While updating your operating system, you can also opt to receive updates for drivers or other office applications.
On the corporate side, tools like Windows Server Update Services (WSUS), System Center Configuration Manager (SCCM), and other third-party applications help keep endpoints up-to-date with the latest security patches. These tools not only handle regular Windows system patches but also manage updates for widely used software like Java, Firefox, and other applications currently in use.
Unix/Linux Software Updates
Unlike Microsoft environments, Unix-based systems typically use a package management system to install most third-party applications. The package management and update tools vary depending on the Unix system and the distribution you are using. For example, Debian Linux and SUSE Linux use different package management systems, and FreeBSD uses yet another system.
Despite these differences, there are common themes surrounding package management systems. Usually, each host has a package repository that can be accessed via local tools to install software on the system. The system administrator issues commands to the package management system to install, update, or remove packages. The package management system, based on its configuration, downloads, compiles, or updates the binary files of the desired package and its dependencies (libraries and other applications required to run the desired application).
When the repository of available packages is updated, new versions of previously installed packages appear in the package database. These new version numbers can be compared with the installed version numbers, and a list of applications that need an upgrade can be automatically determined, usually with a single command line. This ease of upgrade using package management means that if there is no strong change control and implementation system for installed applications, the package management system should be used to provide an easy and automatic method of updating all packages on UNIX application servers.
This not only eliminates the need to manually track each application installed on the application servers along with all its associated dependencies but also means that it has been tested and approved to work on this distribution. Of course, individual issues between systems mean that you can’t be sure everything will always work smoothly.
Core Operating System Updates
Most, if not all, UNIX systems have a distinction between the operating system and the applications installed with it. Therefore, the method of keeping the operating system itself up-to-date will be different from other applications. The upgrade method varies from one operating system to another, but upgrade methods fall into two main categories:
Binary Update
Commercial operating systems, in particular, support the binary update application method. In other words, they replace previous versions by distributing pre-compiled binary executable files and libraries copied to the disk. Binary updates cannot use special compiler options and cannot make assumptions about dependencies, but generally require less work and are quick to install.
Source Update
Many open-source operating systems mean that they are compiled locally from a copy of the source code and replace previous versions on disk with these binary files. Source updates take more time and are more complex, but the operating system can include special compiler optimizations and patches.
There is much debate about which system is better, and each has its pros and cons. However, since most of the arguments focus on non-security-related issues, you can continue with the default of your operating system. Operating system updates are generally less frequent than third-party software updates. Additionally, they often cause more significant problems because they require a reboot. Unlike application updates, which can be concretized by updating the kernel or other subsystems loaded only at startup, core operating updates are recommended. Still, security vulnerabilities often require us to update both the operating system and its applications.
As with other patches, having a rollback plan for any major update is crucial. For more information on cybersecurity best practices, you can visit CISA.
