How to Improve Your Cyber Posture by Avoiding Configuration Drift

Configuration drift is a common problem for developers, where slight changes to a system’s actual configuration slowly lead to a deviation from its desired state. It’s usually exacerbated by simply overlooking the measures required to combat it, which might include using a version control system and vigilantly adhering to infrastructure automation workflows.

Configuration drift isn’t only a problem for a system’s functionality, but it can also have serious security implications. It slowly increases the attack surface as unchecked modifications accumulate, potentially leaving hidden vulnerabilities that threat actors could exploit. Even a minor overlooked detail, like forgetting to remove a temporary firewall rule, can be the catalyst for a much larger breach.

In this article, we will cover practical strategies you can implement to reduce configuration drift, so you can boost the overall security posture of your systems.

Embrace Automation in Configuration Management

Manual processes, no matter how well documented, are susceptible to human error and usually lead to inconsistencies over time. That’s one of the key reasons why many DevOps teams are embracing infrastructure as code (IaC) to automate their configuration deployments.

Humans make mistakes, especially with repetitive tasks. Codifying your infrastructure promotes a more reliable, scalable environment where drift is less likely to occur because every environment is consistently built and updated from a single source of truth.

Every environment (development, staging, production) can be configured identically, preventing those “it works in dev but not in prod” scenarios, while also making rollbacks faster when issues do arise.

Additionally, integrating your IaC approach into a CI/CD tool like Jenkins or GitHub Actions will help automatically test, validate, and document changes. Automated pipelines and IaC can work hand in hand to significantly reduce the risk of drift.

Refresh Your State Files

Once automation is implemented, you have to manage it correctly. If you use IaC tools like Terraform and OpenTofu, this means regularly updating the state file where all the information about your managed resources is stored. Doing so ensures that your state remains an accurate reflection of your real-world infrastructure, thereby minimizing configuration drift. 

There are two commands you need to keep your Terraform state file accurate and detect potential drift quickly: terraform plan and terraform refresh.

For identifying configuration drift, it’s actually best to run these two commands in tandem: terraform plan -refresh-only.

The refresh-only flag will show what the changes to the state file would be, safer than using terraform refresh directly which automatically updates the state without prior review.

The output of the command will highlight any resources that are out of sync with your code, giving you the choice to accept or reject those changes. Regularly reviewing and refreshing the state files will minimize unintended security risks, and help your team keep an auditable change history.

Keep an Eye on Your Configuration Changes

Unmonitored configuration changes is what typically creates drift. So, monitoring your infrastructure configurations is just as important as setting them up correctly in the first place.

The best way to go about it is scheduling regular audits and reviews of your infrastructure resources. This can usually be done automatically, depending on where your infrastructure is stored. We already covered Terraform, but there are also automated monitoring capabilities in other services, including AWS, Azure, and third-party tools made for multi-cloud situations.

Using these tools, you can keep a historical log of who, when, and why changes were made, and set up instant notifications when configuration drift or policy violations occur.

For large teams, dashboard-based alerts and weekly reports can keep everyone updated about tweaks while providing clear accountability for every change. This level of transparency makes teams more careful with their actions and assists with root-cause analysis when something goes wrong.

Institute Change Management Policies

Well-established and enforced policies are what drive positive security changes. There are several important change management policies you can implement to address configuration drift. 

The first one would be establishing clear roles and responsibilities about who and when can make changes and under what circumstances. 

An approval process through a ticketing system (for example, Jira) helps document all requested changes and makes sure they are authorized before being implemented. This helps audit not just the change itself but also the decision-making process that led to the change.

Documentation and version control are also key. You can keep all configuration files, scripts, and infrastructure definitions in a version control system like Git, along with description files containing the rationale and impact of each update.

Conclusion

Configuration drift is one of the bigger risks organizations face in an increasingly dangerous threat environment. Even a seemingly slight accidental change, such as opening a port, can leave the door open for attackers.

Implementing infrastructure-as-code and automating your configuration management is a great way to minimize drift and the associated security pitfalls. Prominent IaC tools like Terraform have great drift detection and refresh capabilities that help teams identify discrepancies early and address them before they escalate into cyber risks.