Amazon Web Services SCS-C02 Online Access

https://aws.amazon.com/blogs/security/how-to-use-trust-policies-with-iam-roles/

The most likely cause of the error is that the instance profile for the EC2 instance does not have the s3:PutObject permission for the S3 bucket. This permission is needed to upload logs to the bucket. Therefore, the security engineer should ensure that the instance profile has this permission.

One possible solution is to attach the AWSImageBuilderFullAccess policy to the instance profile for the EC2 instance. This policy grants full access to Image Builder resources and related AWS services, including the s3:PutObject permission for any bucket with “imagebuilder” in its name. However, this policy may grant more permissions than necessary, which violates the principle of least privilege.

Another possible solution is to create a custom policy that only grants the s3:PutObject permission for the specific S3 bucket that is used for logging. This policy can be attached to the instance profile along with the other policies that are required for Image Builder functionality: EC2InstanceProfileForImageBuilder, EC2InstanceProfileForImageBuilderECRContainerBuilds, and AmazonSSMManagedInstanceCore. This solution follows the principle of least privilege more closely than the previous one.

• Ensure that the following policies are attached to the instance profile for the EC2 instance: EC2InstanceProfileForImageBuilder, EC2InstanceProfileForImageBuilderECRContainerBuilds, and AmazonSSMManagedInstanceCore.
• Ensure that the instance profile for the EC2 instance has the s3:PutObject permission for the S3 bucket. This can be done by either attaching the AWSImageBuilderFullAccess policy or creating a custom policy with this permission.

1: Using managed policies for EC2 Image Builder - EC2 Image Builder 2: PutObject - Amazon Simple Storage Service 3: AWSImageBuilderFullAccess - AWS Managed Policy

To address the issue of an Amazon EC2 instance receiving suspicious requests over an open TCP port, the most effective solution is to update the Network Access Control List (NACL) associated with the subnet where the EC2 instance resides. By adding a deny rule for the specific TCP port and source IP addresses involved in the suspicious activity, the security team can effectively block unwanted traffic at the subnet level. NACLs act as a stateless firewall for controlling traffic in and out of subnets, allowing for broad-based traffic filtering. This measure ensures that only legitimate traffic can reach the EC2 instance, thereby enhancing security without affecting the application's availability to other users. It's a more granular and immediate way to block specific traffic compared to modifying security group rules, which are stateful and apply at the instance level.