Mastering AWS Governance: Part 1 - Fine-tune AWS Config & AWS Security Hub
Explore best practices for optimizing AWS Config and AWS Security Hub to reduce alert fatigue, prioritize critical threats, and cut costs.
Published Feb 28, 2025
As cloud environments grow in complexity, maintaining governance and compliance becomes an ever-evolving challenge. AWS Config, and AWS Security Hub are indispensable tools designed to help organizations enforce policies, monitor security posture, and manage multi-account structures effectively. However, the true potential of these services is often underutilized, leading to operational inefficiencies, alert fatigue, and escalating costs.
For cloud architects and engineers, the goal isn’t just to maintain compliance but to do so efficiently while optimizing security and operational performance. This requires a strategic approach—one that balances comprehensive monitoring and governance with cost efficiency and scalability.
In this series, we will explore best practices for configuring and optimizing AWS Config, and AWS Security Hub. It delves into strategies to enhance security posture, operational efficiency, and cost management while maintaining compliance at scale.
AWS Config provides the foundation for configuration monitoring and compliance auditing within AWS environments. It continuously evaluates the state of your resources, ensuring they meet your security and governance requirements. However, a common pitfall is to enable a multitude of rules without strategic planning, leading to overwhelming alerts, increased costs, and operational inefficiencies.
To fully harness AWS Config’s potential, the focus should be on optimizing rule selection, customization, and operational efficiency. This involves selecting rules that provide the most meaningful insights, customizing configurations to fit specific application needs, and managing the lifecycle of these rules to adapt to changing compliance requirements.
Enabling too many AWS Config rules can quickly lead to alert fatigue, where critical alerts are buried under a mountain of less significant notifications. This not only impacts operational efficiency but also increases costs, as each rule execution is billed per evaluation.
The key to effective governance lies in prioritizing high-impact rules that genuinely enhance security posture without overwhelming teams with non-critical alerts. This approach streamlines rule management, improves efficiency, and allows security teams to focus on truly critical issues.
Examples
- S3 Buckets: Enforcing encryption at the bucket level with the S3_BUCKET_ENCRYPTED rule ensures default encryption for all new objects, making object-level checks like S3_OBJECT_ENCRYPTION redundant. Combining this with the S3_BUCKET_PUBLIC_READ_PROHIBITED rule protects data from public exposure while reducing alert noise and evaluation costs.
- Security Groups: Configuring Security Groups to block inbound traffic from public IPs using the INCOMING_SG_NO_PUBLIC_IP rule eliminates the need for redundant Network ACL checks. Pairing this with SG_RESTRICTED_PORTS enhances security for sensitive ports without overlapping rules.
These examples demonstrate how strategic rule consolidation reduces redundancy and optimizes performance. However, organizations should evaluate their security needs to identify additional optimization opportunities.
AWS Config retains configuration history for auditing and compliance. However, excessive retention can lead to significant storage costs. To optimize costs while maintaining compliance:
- Configure Appropriate Retention Periods: Set retention periods based on compliance requirements. For example, retaining configuration history for 90 days might suffice for internal audits, while regulatory compliance may require longer retention.
- Utilize S3 Lifecycle Policies: Store historical data in S3 with lifecycle policies to transition older data to cost-effective storage classes like S3 Glacier.
- Data Lake Integration: For organizations needing long-term retention, consider integrating AWS Config with a data lake for centralized storage and analysis. For example, store AWS Config snapshots in Amazon S3 (Intelligent-Tiering) and move older data to S3 Glacier Deep Archive for cost savings. Query historical data on demand using Amazon Athena without maintaining databases, ensuring long-term retention at minimal cost.
This approach balances cost and compliance by optimizing data retention policies.
AWS Security Hub serves as a central point for aggregating security findings across multiple AWS services, providing a unified view of your organization’s security posture. However, its effectiveness depends heavily on strategic configuration and optimization. Without careful tuning, AWS Security Hub can generate excessive alerts, leading to analysis paralysis and increased operational costs.
The challenge lies in leveraging AWS Security Hub’s powerful threat detection capabilities while minimizing alert fatigue and optimizing costs. This involves precise scoping, severity management, and automation of remediation workflows.
Effective threat detection starts with defining the scope of AWS Security Hub to focus on relevant accounts, regions, and resources. Configuring AWS Security Hub to scan all accounts and regions indiscriminately not only increases costs but also generates unnecessary findings that dilute focus on critical threats.
Limiting AWS Security Hub’s scope to high-risk resources and sensitive accounts significantly reduces noise. Additionally, configuring severity thresholds helps prioritize critical and high-severity findings, ensuring teams are alerted to issues that genuinely require immediate attention.
This example demonstrates how to filter and prioritize high-severity issues. However, other configurations may be more suitable based on organizational needs.
To further enhance operational efficiency, AWS Security Hub can be integrated with AWS EventBridge to automate incident response workflows. This allows high-severity findings to trigger remediation actions, ensuring rapid response and maintaining compliance with security policies.
AWS Security Hub can generate numerous findings, but not all require immediate attention. Implementing intelligent findings suppression helps reduce noise by filtering out non-critical alerts that are known, expected, or deemed low-risk. Utilizing 'Findings Suppression Rules' with precise conditions and expiration dates ensures that only actionable alerts reach security teams.
Suppression rules can also be based on specific resources that are known to require exceptions. For instance, you may have an EC2 instance running with a non-compliant security group due to legacy requirements or a planned migration.
This approach minimizes alert fatigue, enabling teams to focus on genuine threats while maintaining a streamlined incident response workflow. Additionally, periodic reviews of suppression rules ensure they remain relevant as security requirements evolve. For more advanced and automated suppression rules, particularly for bulk operations please refer to the documentation here: Understanding automation rules in Security Hub
AWS Conformance Packs offer a convenient way to enforce compliance, but they can lead to redundant checks and increased costs when overlapping with AWS Security Hub rules. For example, the CIS AWS Foundations Benchmark includes a rule to ensure Multi-Factor Authentication (MFA) is enabled for root accounts (
CIS.1.2). This control is also present in several Conformance Pack templates. If AWS Security Hub is already monitoring this control, it is efficient to remove it from the Conformance Pack, thereby avoiding duplicate evaluations and reducing costs.Best Practice:
- Regularly audit Conformance Pack templates against AWS Security Hub standards to identify and eliminate redundant rules.
- Customize Conformance Packs by excluding rules that AWS Security Hub is already handling, optimizing both cost and operational efficiency.
Deploying AWS Config and AWS Security Hub is just the beginning of a robust cloud security strategy. To maintain a secure, compliant, and cost-effective environment, continuous optimization is crucial. This ongoing effort ensures that security controls are relevant, performance remains optimal, and costs are minimized. Key areas of focus for continuous optimization include:
- Controlling Config Item Growth:
A primary cost factor in AWS Config is the number of Config items recorded. Each tracked configuration change generates a new Config item, which can quickly increase costs in large environments. To optimize spending, it is crucial to record only essential resources and apply custom rules selectively. Additionally, adjusting rule evaluation frequency and leveraging periodic snapshots instead of real-time tracking can help minimize unnecessary recordings. By strategically managing what gets recorded, organizations can maintain compliance while controlling costs effectively. - Periodic Rule Review:
Regularly reviewing and auditing AWS Config rules and AWS Security Hub findings is essential to ensure that they align with your evolving security posture. This includes checking that security standards are up-to-date with industry best practices and adjusting rules to reflect any changes in compliance requirements. By removing obsolete or redundant rules, teams can avoid unnecessary evaluations, ensuring that only pertinent issues are flagged for action. - Performance Tuning:
Performance tuning is crucial to reduce the overhead of AWS Config rules, particularly those utilizing Lambda functions. Fine-tuning Lambda-backed Config rules for more efficient execution can lead to faster evaluations and lower costs. For instance, adjusting the frequency of rule evaluations, optimizing the resource footprint of Lambda functions, or restructuring rules for better performance can reduce delays and resource usage, helping to keep your AWS bills in check. - Incident Response Automation:
Leveraging AWS EventBridge to automate response workflows for high-severity findings is a proactive approach to managing incidents. This can include automatically triggering Lambda functions to remediate non-compliant resources or initiate a notification process to relevant stakeholders. Automation not only accelerates response times but also reduces the manual effort required, ensuring swift and accurate remediation of security incidents. This approach improves efficiency, minimizes human error, and helps maintain a continuous security posture.
By strategically optimizing AWS Config and AWS Security Hub, organizations can not only enhance their security posture but also improve operational resilience and cost efficiency. This ongoing optimization helps organizations stay ahead of potential threats while maintaining a streamlined, cost-effective environment. Rather than seeing governance as just a compliance checkbox, it becomes a strategic enabler of cloud agility, allowing teams to focus on innovation and growth.
In the next part of this series, to be published in the coming weeks, we will delve into advanced AWS governance strategies, including Event-Driven integrations, IAM Access optimization, enhanced threat detection, and further cost optimization across the broader AWS governance ecosystem. Stay tuned for deeper insights into building a truly resilient and efficient cloud security posture.
- Ajith Joseph, Specialist Master, Deloitte LLP
- Najeeb Danish, Specialist Leader, Deloitte LLP
------------------------------------------------------------------------------------------------------------------------
Disclaimer: Please note that AWS technology is constantly evolving, and new features may be available since the release of this blog post. It's recommended to review the latest documentation to determine the most suitable solutions for your specific needs. This blog is a reference guide only. Additionally, ensure that the proposed solutions comply with your organization's security and compliance requirements, as some services may be relatively new and may not be fully compliant with all industry standards.