Identity and Access Management (IAM) is the backbone of Cloud security in AWS. Just as EC2 powers your compute infrastructure, IAM governs who can access what, under which conditions, and with which level of privilege. It plays a critical role in ensuring the right people, and only the right people, have the appropriate level of access to resources across your AWS environment.
Unlike traditional on-premise access control models, IAM in AWS is built for scale, agility, and automation. Whether you’re managing a handful of users or a complex organisation with multiple teams and workloads across regions and accounts, IAM enables you to enforce consistent security policies, monitor access, and respond quickly to threats without compromising operational efficiency.
At Cloud Elemental, we work hand-in-hand with clients to design and implement secure, scalable, and auditable IAM frameworks. We help organisations embed least-privilege principles, leverage federation and automation, and adopt modern identity practices – ensuring that access to AWS resources is both seamless and secure. With our guidance, customers reduce risk, accelerate onboarding, and maintain full visibility and control over their Cloud environments.
Why a Standard IAM Access Model Matters
Before diving into the “how”, let’s revisit the “why”:
- Security: Misconfigured IAM access is one of the most common causes of data breaches.
- Scalability: A standard model ensures users and systems can be onboarded and off-boarded seamlessly.
- Auditability: Customers must be able to trace every access event back to an identity.
- Trust: We must demonstrate that we treat customer environments with the same care as our own.
Recommended Standard IAM Practices for Accessing Customer AWS Accounts
1. Use IAM Roles Instead of IAM Users
Best practice: Avoid long-lived IAM users and access keys. Use IAM roles with short-lived temporary credentials via AWS Security Token Service (STS).
IAM users pose a security risk due to persistent credentials. Once an access key is leaked, it can be exploited indefinitely as it allows direct access to your environment.
IAM roles allow secure, auditable, and time-bound access, especially for cross-account scenarios or internal team access.
Use
AssumeRolepatterns and enforce MFA for elevated roles.
Bad: Creating IAM users with Admin privileges and storing their access keys in local machines or scripts.
Good: Using an IAM role assumed via AWS CLI with session duration limited to 1 hour and requiring MFA.
2. Follow the Principle of Least Privilege
Best practice: Only grant the exact permissions required – and no more.
Start with deny-all and build up permission sets incrementally.
Use IAM policies that are tightly scoped, avoiding
*wildcards inActionorResourceunless absolutely necessary.Review and refine policies regularly as roles evolve.
Bad:
{ "Effect": "Allow", "Action": "*", "Resource": "*" }
Good:
{ "Effect": "Allow", "Action": ["s3:GetObject"], "Resource": ["arn:aws:s3:::mybucket/reports/*"] }
3. Enforce Role Segmentation and Access Boundaries
Best practice: Design IAM roles around clear, job-specific responsibilities. Avoid “god-mode” roles or overly broad access.
Use roles per function/team/environment (e.g.,
DevReadOnly,ProdDeploy,AuditAccess).Separate development, staging, and production access.
Use Service Control Policies (SCPs) in AWS Organisations to enforce boundaries globally.
Example: Developers assume a
DevOpsDeployerrole with scoped access to specific CodePipeline and ECS services only in dev accounts.
4. Enable MFA Everywhere - Especially for Privileged Access
Best practice: Require Multi-Factor Authentication (MFA) for all users and roles with sensitive or elevated permissions.
Use MFA on IAM users (if they must exist), especially for administrative actions.
Require MFA conditions in IAM policies using
Conditionblocks (e.g.,aws:MultiFactorAuthPresent).For CLI usage, enforce MFA session tokens when assuming roles.
5. Use Permission Boundaries to Prevent Privilege Escalation
Best practice: Implement permissions boundaries for IAM roles created dynamically (e.g., by CI/CD systems or delegated administrators).
A permissions boundary is a policy that limits the maximum permissions a role can have, even if its attached policies are broader.
This is critical when you allow other services or teams to create/manage roles on your behalf.
Example: You allow a CI/CD pipeline to create IAM roles, but enforce a permission boundary that prevents roles with
iam:*orkms:*permissions.
6. Audit and Monitor IAM Activity
Best practice: Continuously audit IAM changes and monitor who is accessing what.
Enable CloudTrail across all accounts to track IAM usage and policy changes.
Use Access Analyzer to detect policies granting unintended external access.
Use IAM Access Advisor to identify unused permissions and prune over-provisioned roles.
Pro tip: Integrate CloudTrail with a SIEM or GuardDuty for real-time detection of suspicious IAM behaviour.
7. Standardise Role Assumption for Consultants and Partners
Best practice: Establish a standard, consistent process for how external users (e.g., consultants, support teams) access your AWS environment.
Provide a pre-defined IAM role (e.g.,
PartnerSupportReadOnly) with scoped permissions.Require that all external access go through
AssumeRoleusing temporary credentials.Never share persistent credentials with third parties.
8. Avoid Resource Wildcards (*) Unless Necessary
Best practice: Avoid blanket permissions like Resource: "*", especially on sensitive services (IAM, KMS, CloudFormation).
Always scope policies down to exact resources (
arn:aws:s3:::mybucket/*, etc.).If resource scoping isn’t possible, use Condition blocks to restrict access (e.g., by
aws:RequestedRegionoraws:TagKeys).
Example:
"Condition": { "StringEquals": { "aws:RequestedRegion": "eu-west-1" } }
9. Tag IAM Resources for Governance and Visibility
Best practice: Apply tags to all IAM roles, policies, and users to support cost tracking, security reviews, and access audits.
Use consistent tagging standards:
Environment,Owner,CreatedBy,ExpirationDate.Enforce tagging at creation using Tag Policies.
10. Rotate and Deactivate Unused Credentials
Best practice: Enforce key rotation policies and deactivate unused credentials.
Use AWS Config or custom automation to flag access keys older than 90 days.
Deactivate keys not used in the last 30 days.
Prefer IAM roles over keys – if keys must exist, automate their rotation.
Leveraging Identity Federation for Enterprises
Leveraging a customer’s existing enterprise identity system, such as Active Directory (AD) or a Cloud-based identity provider (IdP) like Azure AD or Okta, is a best practice when granting access to Cloud environments.
By implementing identity federation via SAML 2.0 or AWS IAM Identity Center (formerly AWS SSO), organisations can map internal user identities to IAM roles in AWS. This enables seamless, temporary, and auditable access without the need to manage standalone IAM users. The integration ensures that workforce identities adhere to existing governance structures – such as password policies, MFA enforcement, and access revocation upon role changes – making access management both secure and scalable.
Adopting identity federation significantly reduces the risk associated with long-term credentials, enables centralised control, and simplifies compliance with regulatory standards such as ISO 27001 and NIST 800-53. Additionally, it allows enterprises to maintain consistent user authentication and authorisation across multi-Cloud and hybrid environments, reinforcing least privilege and strengthening access accountability.
Through our AWS Well-Architected Framework (WAF) reviews, we help organisations strengthen their infrastructure by embedding resilience, operational excellence, and automated best practices into every layer of their Cloud environment.
As an AWS Advanced Tier Partner, we can also help unlock AWS funding programmes to subsidise your review, making it easier to identify risks, strengthen recovery processes, and build customer trust before an incident ever occurs.
To set up a free AWS WAF consultation with us, visit our information page, or check out our AWS Marketplace listing below.
