AWS IAM best practices to secure your resources...
Published: 2023-03-13 10:47:38

AWS IAM (Identity and Access Management) is a web service that enables you to securely control access to AWS resources. IAM enables you to create and manage AWS users and groups and assign policies to control the level of access that each user or group has to specific AWS resources.

## Key Components of AWS IAM

**User Management**: IAM enables you to create and manage individual users within your AWS account. This enables you to control who has access to your AWS resources.

**Group Management**: IAM enables you to create and manage groups of users. This enables you to assign policies to groups, rather than having to assign policies to individual users.

**Access Management**: IAM enables you to control access to AWS resources using permissions. Permissions are defined using policies, which specify which actions a user or group can perform on specific AWS resources.

**Multi-factor Authentication (MFA)**: IAM enables you to require MFA for users when they sign into your AWS account. MFA provides an extra layer of security beyond a user's password.

**Integration with AWS Services**: IAM is integrated with many AWS services, such as Amazon S3, Amazon EC2, and Amazon RDS. This enables you to control access to these services using IAM policies.

**Auditing and Logging**: IAM provides detailed logging and auditing of all user activity within your AWS account. This enables you to monitor user activity and detect any suspicious behavior.

Overall, AWS IAM provides a robust set of tools for managing access to your AWS resources, helping you maintain security and compliance.

## Key features of AWS IAM

• **Authentication**: AWS IAM lets you create and manage identities such as users, groups, and roles, meaning you can issue and enable authentication for resources, people, services, and apps within your AWS account. 

• **Authorization**: Access management or authorization in IAM is made of two primary components: Policies and Permissions. In the next section, we’ll also look at each of these.

• **Fine-grained permissions**: Consider this — you want to provide the sales team in your organization access to billing information, but also need to allow the developer team full access to the EC2 service, and the marketing team access to selected S3 buckets. Using IAM, you can configure and tune these permissions as per the needs of your users.

• **Shared access to AWS accounts**: Most organizations have more than one AWS account, and at times need to delegate access between them. IAM lets you do this without sharing your credentials, and more recently, AWS released Control Tower to further simplify multi-account configurations. We also published a quick, hands-on tutorial on Securing Multi-Account Access on AWS.

• **AWS Organizations**: For fine-grained control for multiple AWS accounts, you can use AWS Organizations to segment accounts into groups and assign permission boundaries.

• **Identity Federation**: Many times, your organization will need to federate access from other identity providers such as Okta, G Suite, or Active Directory. IAM enables you to do this with a feature called Identity Federation

**By following these best practices, you can help ensure that your AWS resources are secure and compliant with industry standards and regulations. **

• **Avoid the use of root account unless strictly necessary**: Do not use the root account for day-to-day administration activities. By default, the root account user has access to all resources for all AWS services and its best practice to create IAM users with least privilege access. Additionally, do not create access keys for the root account unless strictly necessary. Finally, set up monitoring to detect and alert on root account activity, and 
ensure hardware-based MFA is set up for root account access.

• **Use temporary credentials**: Never share your credentials with anyone. It’s advisable to create individual users for anyone who has access requirements and even better use temporary credentials. Dynamically generated credentials that expire after a configurable interval, are a great way to tackle this. You can visit our practical tutorial on Securing Multi-Account Access on AWS for detailed instructions on this.

• **Embrace the least privilege principle and review all IAM permissions periodically**: It is important to follow the security principle of least privilege, which means that if a user doesn’t need to interact with a resource, then it is best not to provide them access to that resource. IAM permissions allow for very granular access controls, so avoid the use of policy statements that grant access to all actions, all principals, or all resources. 
Additionally, use the IAM Access Advisor regularly to ensure that all permissions assigned to a particular user are indeed being used.

• **Enforce the least privilege principle to be implemented bi-directionally**: Many AWS resources (such as S3 buckets) can have their access policy attached directly. Don’t fall into the trap of thinking that because access is tightly controlled in one direction (i.e., an IAM Role that grants very specific permissions), that you should be less rigid in the other direction (for example, when an S3 bucket access policy grants read access to all entities in your account). Optimally use both sides of the least privilege principle to achieve favorable outcomes.

• **Monitor account activity regularly using IAM Access Analyzer and AWS CloudTrail**: In addition to what we discussed about the newly released IAM Access Analyzer, the good old AWS CloudTrail is an excellent tool to monitor all activities in your account. You can easily use CloudTrail logs to identify suspicious activity and take necessary actions depending on your findings. You will find our deep-dive, practical tutorial on AWS Security Logging with CloudTrail interesting with step-by-step instructions to help you do this.

•**Use Multi-Factor Authentication (MFA)**: Enable MFA to build an additional layer of security for interaction with the AWS API.

• **Enforce strong passwords**: Enforce strong passwords by configuring account password policy that involves password rotation, discourages the use of old passwords, only allows alphanumeric characters, and more.

• **Monitor and Review Permissions Regularly**: Regularly review permissions assigned to users and groups to ensure that they are still needed and appropriate. IAM provides reports and tools to help identify and remediate permissions issues.

• **Use IAM Roles for EC2 Instances**: Use IAM roles to grant temporary permissions to EC2 instances instead of storing credentials on the instance itself. This reduces the risk of credential exposure in case the instance is compromised.

• **Enable AWS CloudTrail**: AWS CloudTrail logs all API activity in your AWS account, including IAM actions. This provides a trail of activity that can be used for security analysis, resource change tracking, and compliance auditing.

• **Use IAM Policy Conditions**: Use IAM policy conditions to further restrict access based on context, such as IP address or time of day. This adds an additional layer of security beyond traditional permissions.

• **Enable AWS Security Hub**: AWS Security Hub provides a comprehensive view of security alerts and compliance status across your AWS accounts. It can help you identify security issues and provide recommendations for remediation.