The Top 5 AWS Misconfigurations That Lead to a Breach

Amazon Web Services (AWS) offers incredible power and flexibility, but its complexity can lead to simple misconfigurations with disastrous consequences. The "Shared Responsibility Model" means that while AWS secures the cloud, you are responsible for securing what's *in* the cloud. Based on our assessments, these are five of the most common and dangerous misconfigurations we see.

1. Public S3 Buckets

This is the classic, yet still incredibly common, cloud security failure. By default, S3 buckets are private, but a single checkbox can expose terabytes of sensitive data to the entire internet. Attackers constantly scan for open buckets, making this a critical check for every organization.

2. Overly Permissive IAM Roles and Policies

The principle of least privilege is paramount in the cloud. We often find IAM (Identity and Access Management) users or roles with wildcard permissions (`"*:*"`) or excessive administrative rights. If an attacker compromises these credentials, they gain extensive control over your environment.

3. Unrestricted Security Group Rules

A security group acts as a virtual firewall for your EC2 instances. A common mistake is allowing unrestricted inbound access (e.g., from `0.0.0.0/0`) on sensitive ports like SSH (22) or RDP (3389). This effectively puts your server's login screen on the public internet, inviting brute-force attacks.

A misconfigured security group is the cloud equivalent of leaving your front door wide open with a "Welcome" sign.

4. Lack of Logging and Monitoring (CloudTrail)

AWS CloudTrail logs all API activity within your account. We frequently find that CloudTrail is either not enabled, not configured to log across all regions, or its logs are not protected from tampering. Without these logs, it's nearly impossible to detect a breach or perform a forensic investigation after an incident.

5. Exposed EC2 Instance Metadata

Every EC2 instance has a metadata service that provides information about the instance itself. If a web application on that instance has a Server-Side Request Forgery (SSRF) vulnerability, an attacker can trick the server into querying this service and stealing the temporary credentials attached to the instance's IAM role, often leading to a full account compromise.