SY0-701 Security+: 1.3 Technical Change Management

Technical Change Management

Involves implementing changes within your environment, which typically relies on technical staff to carry out the necessary modifications.

• Upgrades are rarely straightforward, often involving multiple moving parts, and may require separate events for each component.

• While change management focuses on identifying what needs to change, the technical team is responsible for determining how to make those changes.

Allow List / Deny List Example

A technician may be tasked with modifying an allow list or deny list as part of security management. Since any application can pose a threat—such as vulnerabilities, trojans, or malware—a security policy can control which apps are allowed to execute.

• An allow list is highly restrictive, only permitting applications that have been explicitly approved to run on workstations. If an application is not named on the list, it cannot execute.

• A deny list offers more flexibility. It allows any application to run, except for those specifically identified as prohibited.

  • In this sense, antivirus and anti-malware systems can be seen as a large deny list, blocking certain types of harmful code while allowing everything else to run.

Restricted Activities

Change management dictates that you can only make changes to components specifically listed in the change control document. You cannot alter other applications simply because the change window is open.

• The scope of a change is crucial as it defines exactly which components are affected.

• Scope may need to be adjusted during the change window, policies may allow for decisions like modifying certain files to complete a relatively simple modification

• It’s impossible to predict all potential outcomes, which is why having a well-documented change control process is essential.

Downtime

An inevitable part of many changes, as services may become unavailable during the process.

• To minimize disruption, significant changes are often scheduled during overnight hours or when users are not actively working on the affected application.

  • For organizations that operate 24/7, finding a suitable change window where downtime is acceptable can be challenging.

• Switch to a secondary system, upgrade the primary system, and then switch back once the upgrade is complete

  • If issues arise, the secondary system can be activated, ensuring that no changes were made to it.

• Communicate any potential outages by sending emails and calendar updates to ensure everyone is aware of the planned downtime during the change window

Restarts

Before bringing everything back online, it’s often necessary to reboot the system.

• May involve rebooting the operating system, power cycling the switch, or restarting a service

• When dealing with services, a simple stop and restart of the service or daemon might be required, which can take anywhere from seconds to minutes

• For applications, users may need to log out, close the application entirely, and then restart it with the updated version

Legacy Applications

Those that predate your involvement and will likely remain long after you're gone. Often no longer supported by the developer, these applications now fall under your responsibility for maintenance and troubleshooting.

• While there may be a fear of the unknown, the best approach is to face those fears by thoroughly documenting the system.

• Though these applications may be quirky, taking the time to understand and document them can reveal that they’re not as difficult to manage as they seem.

• By creating specific processes and procedures, you'll gradually become the expert

  • Not only will you gain expertise, but you'll also empower others in your organization to support the system more effectively.

Documentation

Can be challenging, as it often becomes outdated quickly.

• This includes updating diagrams, network configurations, and addresses, as well as revising policies and procedures.

• The introduction of new systems may require the creation of new procedures to ensure everything remains well-documented and manageable

• Regularly maintaining documentation ensures that changes are properly tracked and the system stays organized

Version Control

Essential for tracking changes to files or configuration data over time, allowing you to easily revert to previous settings if necessary.

• It’s particularly useful for managing different versions of various systems and applications.

• There are many opportunities to apply version, including router configurations, Windows OS patches, and application registry entries.

• Some devices and operating systems provide built-in version control features

  • You might consider installing a third-party version control management system, enabling you to track changes across all systems and clearly understand when changes are made and their effects.